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Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

ARM - Measurement - Aerosol optical properties  

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

properties properties 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 properties The optical properties of aerosols, including asymmetry factor, phase-function, single-scattering albedo, refractive index, and backscatter fraction. 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 recorded for diagnostic or quality assurance purposes. ARM Instruments CSPHOT : Cimel Sunphotometer NEPHELOMETER : Nephelometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

2

Optical, physical, and chemical properties of springtime aerosol...  

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

Optical, physical, and chemical properties of springtime aerosol over Barrow Alaska in 2008. Optical, physical, and chemical properties of springtime aerosol over Barrow Alaska in...

3

Atmospheric Aerosol Optical Properties in the Persian Gulf  

Science Journals Connector (OSTI)

Aerosol optical depth measurements over Bahrain acquired through the ground-based Aerosol Robotic Network (AERONET) are analyzed. Optical depths obtained from ground-based sun/sky radiometers showed a pronounced temporal trend, with a maximum ...

Alexander Smirnov; Brent N. Holben; Oleg Dubovik; Norm T. O'Neill; Thomas F. Eck; Douglas L. Westphal; Andreas K. Goroch; Christophe Pietras; Ilya Slutsker

2002-02-01T23:59:59.000Z

4

Radiative Effects of Dust Aerosols, Natural Cirrus Clouds and Contrails: Broadband Optical Properties and Sensitivity Studies  

E-Print Network [OSTI]

This dissertation aims to study the broadband optical properties and radiative effects of dust aerosols and ice clouds. It covers three main topics: the uncertainty of dust optical properties and radiative effects from the dust particle shape...

Yi, Bingqi

2013-07-09T23:59:59.000Z

5

DISSERTATION THE OPTICAL, CHEMICAL, AND PHYSICAL PROPERTIES OF AEROSOLS AND  

E-Print Network [OSTI]

AND GASES EMITTED BY THE LABORATORY COMBUSTION OF WILDLAND FUELS Biomass burning is a major source of trace BY THE LABORATORY COMBUSTION OF WILDLAND FUELS Submitted by Gavin R. McMeeking Department of Atmospheric Science PROPERTIES OF AEROSOL AND GASES EMITTED BY THE LABORATORY COMBUSTION OF WILDLAND FUELS BE ACCEPTED

Pierce, Jeffrey

6

Characteristics of aerosol optical properties in pollution and Asian dust episodes  

E-Print Network [OSTI]

Characteristics of aerosol optical properties in pollution and Asian dust episodes over Beijing, China Chenbo Xie,1,2 Tomoki Nishizawa,2, * Nobuo Sugimoto,2 Ichiro Matsui,2 and Zifa Wang3 1 Atmospheric for Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, Anhui

7

Evolution of the optical properties of biomass-burning aerosol during the 2003 southeast Australian bushfires  

Science Journals Connector (OSTI)

During January and February 2003, drought conditions led to major bushfires across southeast Australia, causing considerable damage. We have examined aerosol optical depth (AOD) data...

Radhi, Majed; Box, Michael A; Box, Gail P; Gupta, Pawan; Christopher, Sundar A

2009-01-01T23:59:59.000Z

8

Investigation of the optical and cloud forming properties of pollution, biomass burning, and mineral dust aerosols  

E-Print Network [OSTI]

properties of a biomass burning aerosol generated from fires on the Yucatan Peninsula. Measured aerosol size distributions and size-resolved hygroscopicity and volatility were used to infer critical supersaturation distributions of the distinct particle types...

Lee, Yong Seob

2006-08-16T23:59:59.000Z

9

Correlations Between Optical, Chemical and Physical Properties...  

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

Biomass Burn Aerosols. Correlations Between Optical, Chemical and Physical Properties of Biomass Burn Aerosols. Abstract: Single scattering albedo (?) and Angstrom...

10

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 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 substance in atmospheric aerosol is soot (crystal carbon), which strongly affects the atmospheric transparency, albedo of clouds, and snow cover. The non-selective absorption by finely dispersed soot aerosol is considered to be one of the most plausible reasons for the appearance of

11

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 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 University of Maryland College Park, Maryland D. Covert and R. Elleman University of Washington Seattle, Washington J. Eilers, P. Pilewskie, and A. Strawa National Aeronautics and Space Administration Ames, Research Center Moffett Field, California R. A. Ferrare

12

Geometrical Optics of Dense Aerosols  

SciTech Connect (OSTI)

Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

2013-04-24T23:59:59.000Z

13

AEROgui: A graphical user interface for the optical properties of aerosols  

Science Journals Connector (OSTI)

Atmospheric aerosols have an uncertain effect on climate, and serious impact on human health. The uncertainty in the aerosols role on climate has several sources. First, aerosols present a great spatial and temporal variability. The spatial variability ...

R. Pedrós; J.L. Gómez-Amo; C.R. Marcos; M.P. Utrillas; S. Gandía; F. Tena; J.A. Martinez Lozano

14

E-Print Network 3.0 - aerosol optical properties Sample Search...  

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

the U.S. Department of Energy under Contract No. DE-AC02-98CH10886. Summary: ) of the solar radiation back to space, and an indirect one by determining cloud optical properties...

15

Aerosol optical and hygroscopic properties during TexAQS-GoMACCS 2006 and their impact on aerosol  

E-Print Network [OSTI]

by diesel-fueled mobile sources and from the numerous coal- fired industries and power generation stations August thru 11 September 2006) with a number of gas and aerosol instru- ments deployed to measure air and power plants, with emissions rich in reactive volatile organic compounds (VOCs) and NOX [Ryerson et al

16

March 14, 2011 NIST Aerosol Metrology Workshop Optical Properties: The Global  

E-Print Network [OSTI]

are difficult without involving satellite measurements Correspondence with satellite measurements require. Improved regional forecasts of both weather and air quality #12;GAW Aerosol Lidar Observation Network

17

Aerosol optical properties and their radiative effects in northern Zhanqing Li,1,2,3  

E-Print Network [OSTI]

and may also affect the hydrologic cycle. By scattering and absorbing solar radiative energy, aerosols regions. The East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST-AIRE on climate over China. This study presents some preliminary results using continuous high-quality

Dickerson, Russell R.

18

Variations in organic aerosol optical and hygroscopic properties upon heterogeneous OH oxidation  

E-Print Network [OSTI]

Measurements of the evolution of organic aerosol extinction cross sections (?[subscript ext]) and subsaturated hygroscopicity upon heterogeneous OH oxidation are reported for two model compounds, squalane (a C30 saturated ...

Cappa, Christopher D.

19

ARM - Measurement - Aerosol optical depth  

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

depth 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 those recorded for diagnostic or quality assurance purposes. ARM Instruments HSRL : High Spectral Resolution Lidar MPL : Micropulse Lidar MFRSR : Multifilter Rotating Shadowband Radiometer NIMFR : Normal Incidence Multifilter Radiometer Field Campaign Instruments AOS-PMFOV : Acoustical Optical Spectrometer-Photometer with Multiple

20

The Influence of Fog and Airmass History on Aerosol Optical, Physical and Chemical Properties at Pt. Reyes National Seashore  

SciTech Connect (OSTI)

This paper presents an analysis of the aerosol chemical composition, optical properties and size distributions for a range of conditions encountered during a field measurement campaign conducted between July 7-29, 2005 at Point Reyes National Seashore, north of San Francisco, CA. Observations are partitioned into one-hour periods when conditions were ‘clear’ or ‘foggy’ to identify evidence of cloud processing of aerosols. During the first half of the campaign (July 7-18), conditions at the site were largely maritime. However flow during the second half of the campaigns (July 18-29) was influenced by a thermal trough that added a cyclonic twist to the incoming marine air, bringing it from the south with a more extensive over-land trajectory. Neither flow regime was associated with air coming from the San Francisco Bay area to the south. Measurements by an Aerodyne aerosol mass spectrometer (AMS) of the equivalent molar ratio of ammonium to the sum of sulfate, nitrate and chloride made before the onset of the thermal trough on July 18th were associated with acidic or near-neutral particles. Measurements made after July 18th appear to have excess ammonium. The AMS measurements of mass loading were an order of magnitude less than those reported by a nearby IMPROVE station. However, the AMS measures only non-refractory particles between 0.1 µm and 1 µm, which would not include sea salt. In contrast, the IMPROVE station employs filter-based techniques to measure mass for all particles < 2.5 µm. Assuming chlorine is associated with large sea salt particles at Pt. Reyes and removing this value from the IMPROVE data resulted in good agreement in the total mass fraction between these two techniques,, indicating the importance of sea salt mass in particles greater than 1 µm. Model calculations of the equilibrium gas-phase mixing ratio of NH3 suggest very high values which we attribute to agricultural practices within the park. Reported as an incidental finding is evidence for the cloud droplet activation of large particles (diameter >0.2 mm) with a corresponding reduction in the single scattering albedo of the non-activated particles, followed by a return in the particle size spectrum to the pre-fog conditions immediately afterwards.

Berkowitz, Carl M.; Berg, Larry K.; Yu, Xiao-Ying; Alexander, M. L.; Laskin, Alexander; Zaveri, Rahul A.; Jobson, Bertram Thomas; Andrews, Elisabeth; Ogren, John A.

2011-04-05T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processing  

Science Journals Connector (OSTI)

...12), or engine combustion (16...mass, we draw fundamental conclusions of atmospheric...particles from diesel combustion by using combined...Properties of jet engine combustion particles...of carbon and diesel soot particles...vehicle with a diesel oxidation catalyst . J...Boubel RW ( 1994 ) Fundamentals of Air Pollution...

Renyi Zhang; Alexei F. Khalizov; Joakim Pagels; Dan Zhang; Huaxin Xue; Peter H. McMurry

2008-01-01T23:59:59.000Z

22

E-Print Network 3.0 - aerosol properties in-canopy Sample Search...  

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

in-canopy Page: << < 1 2 3 4 5 > >> 1 Quantitative Assessments of Radiative and Optical Properties of Marine Biogenic Aerosol PI: N. Meskhidze (NCSU) Summary: Quantitative...

23

Cloud Scavenging Effects on Aerosol Radiative and Cloud-nucleating Properties - Final Technical Report  

SciTech Connect (OSTI)

The optical properties of aerosol particles are the controlling factors in determining direct aerosol radiative forcing. These optical properties depend on the chemical composition and size distribution of the aerosol particles, which can change due to various processes during the particles’ lifetime in the atmosphere. Over the course of this project we have studied how cloud processing of atmospheric aerosol changes the aerosol optical properties. A counterflow virtual impactor was used to separate cloud drops from interstitial aerosol and parallel aerosol systems were used to measure the optical properties of the interstitial and cloud-scavenged aerosol. Specifically, aerosol light scattering, back-scattering and absorption were measured and used to derive radiatively significant parameters such as aerosol single scattering albedo and backscatter fraction for cloud-scavenged and interstitial aerosol. This data allows us to demonstrate that the radiative properties of cloud-processed aerosol can be quite different than pre-cloud aerosol. These differences can be used to improve the parameterization of aerosol forcing in climate models.

Ogren, John A.; Sheridan, Patrick S.; Andrews, Elisabeth

2009-03-05T23:59:59.000Z

24

E-Print Network 3.0 - aerosol chemical vapor Sample Search Results  

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

chemical and microphysical properties influence aerosol optical properties and radiative effects... distribution of aerosol extensive and intensive properties will aid ......

25

Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols  

SciTech Connect (OSTI)

We present the laboratory and ambient photoacoustic (PA) measurement of aerosol light absorption coefficients at ultraviolet wavelength (i.e., 355 nm) and compare with measurements at 405, 532, 870, and 1047 nm. Simultaneous measurements of aerosol light scattering coefficients were achieved by the integrating reciprocal nephelometer within the PA's acoustic resonator. Absorption and scattering measurements were carried out for various laboratory generated aerosols, including salt, incense, and kerosene soot to evaluate the instrument calibration and gain insight on the spectral dependence of aerosol light absorption and scattering. Ambient measurements were obtained in Reno, Nevada, between 18 December 2009 and 18 January 2010. The measurement period included days with and without strong ground level temperature inversions, corresponding to highly polluted (freshly emitted aerosols) and relatively clean (aged aerosols) conditions. Particulate matter (PM) concentrations were measured and analyzed with other tracers of traffic emissions. The temperature inversion episodes caused very high concentration of PM{sub 2.5} and PM{sub 10} (particulate matter with aerodynamic diameters less than 2.5 {mu}m and 10 {mu}m, respectively) and gaseous pollutants: carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO{sub 2}). The diurnal change of absorption and scattering coefficients during the polluted (inversion) days increased approximately by a factor of two for all wavelengths compared to the clean days. The spectral variation in aerosol absorption coefficients indicated a significant amount of absorbing aerosol from traffic emissions and residential wood burning. The analysis of single scattering albedo (SSA), Angstrom exponent of absorption (AEA), and Angstrom exponent of scattering (AES) for clean and polluted days provides evidences that the aerosol aging and coating process is suppressed by strong temperature inversion under cloudy conditions. In general, measured UV absorption coefficients were found to be much larger for biomass burning aerosol than for typical ambient aerosols.

Gyawali, Madhu S.; Arnott, W. Patrick; Zaveri, Rahul A.; Song, Chen; Moosmuller, H.; Liu, Li; Mishchenko, M.; Chen, L-W A.; Green, M.; Watson, J. G.; Chow, J. C.

2012-03-08T23:59:59.000Z

26

Hyperspectral Aerosol Optical Depths from TCAP Flights  

SciTech Connect (OSTI)

4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research), the world’s 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 4STAR’s spatially-resolved high-frequency hyperspectral products as a reliable tool for climate studies and satellite validation.

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.

2013-11-13T23:59:59.000Z

27

Temporal Variability of Aerosol Properties during TCAP: Impact on Radiative Forcing  

SciTech Connect (OSTI)

Ground-based remote sensing and in situ observations of aerosol microphysical and optical properties have been collected during summertime (June-August, 2012) as part of the Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/), which was supported by the U.S. Department of Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) Program (http://www.arm.gov/). The overall goal of the TCAP field campaign is to study the evolution of optical and microphysical properties of atmospheric aerosol transported from North America to the Atlantic and their impact on the radiation energy budget. During TCAP, the ground-based ARM Mobile Facility (AMF) was deployed on Cape Cod, an arm-shaped peninsula situated on the easternmost portion of Massachusetts (along the east coast of the United States) and that is generally downwind of large metropolitan areas. The AMF site was equipped with numerous instruments for sampling aerosol, cloud and radiative properties, including a Multi-Filter Rotating Shadowband Radiometer (MFRSR), a Scanning Mobility Particle Sizer (SMPS), an Aerodynamic Particle Sizer (APS), and a three-wavelength nephelometer. In this study we present an analysis of diurnal and day-to-day variability of the column and near-surface aerosol properties obtained from remote sensing (MFRSR data) and ground-based in situ measurements (SMPS, APS, and nephelometer data). In particular, we show that the observed diurnal variability of the MFRSR aerosol optical depth is strong and comparable with that obtained previously from the AERONET climatology in Mexico City, which has a larger aerosol loading. Moreover, we illustrate how the variability of aerosol properties impacts the direct aerosol radiative forcing at different time scales.

Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Fast, Jerome D.; Michalsky, Joseph J.; Lantz, K.; Hodges, G. B.

2013-11-01T23:59:59.000Z

28

Tropospheric Aerosol Optical Thickness from the GOCART Model and Comparisons with Satellite and Sun Photometer Measurements  

Science Journals Connector (OSTI)

The Georgia Institute of Technology–Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model is used to simulate the aerosol optical thickness ? for major types of tropospheric aerosols including sulfate, dust, organic carbon ...

Mian Chin; Paul Ginoux; Stefan Kinne; Omar Torres; Brent N. Holben; Bryan N. Duncan; Randall V. Martin; Jennifer A. Logan; Akiko Higurashi; Teruyuki Nakajima

2002-02-01T23:59:59.000Z

29

ARM - Evaluation Product - Aerosol Optical Depths from SASHE  

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

ProductsAerosol Optical Depths from SASHE ProductsAerosol Optical Depths from SASHE Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Aerosol Optical Depths from SASHE Site(s) PVC SGP General Description The Shortwave Array Spectroradiometer Hemispheric (SASHE) is a ground-based instrument that measures both direct and diffuse shortwave irradiance. In this regard, the instrument is similar to the multifilter rotating shadowband radiometer (MFRSR)-an instrument that has been in the ARM Facility stable for more than 15 years. However, the two instruments differ significantly in wavelength resolution and range. In particular, the SASHE provides hyperspectral measurements from about 350 nm to 1700 nm at a wavelength resolution from 1 to several nanometers, while the MFRSR only

30

Correction to “Hyperspectral Aerosol Optical Depths from TCAP Flights”  

SciTech Connect (OSTI)

In the paper “Hyperspectral aerosol optical depths from TCAP flights” by Y. Shinozuka et al. (Journal of Geophysical Research: Atmospheres, 118, doi:10.1002/2013JD020596, 2013), Tables 1 and 2 were published with the column heads out of order. Tables 1 and 2 are published correctly here. The publisher regrets the error.

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.

2014-02-16T23:59:59.000Z

31

Atmospheric Aerosols Aging Involving Organic Compounds and Impacts on Particle Properties  

E-Print Network [OSTI]

) and chemical reactions (oxidation of particles by gas-phase oxidants and heterogeneous reactions between gas molecules and particles).5 For example, when initially formed, soot particles are hydrophobic and fractal in morphology, with low effective density... particles have a ? value of 1.0; whereas fractal ones will have ? > 1.0. Measurements of Aerosol Optical Properties The optical system consisted of a commercial integrating Nephelometer (Model 3563, TSI) and a CRDS connected in series.20 The particles...

Qiu, Chong

2013-02-01T23:59:59.000Z

32

Single-scattering properties of tri-axial ellipsoidal mineral dust aerosols: A database for application to radiative transfer calculations  

E-Print Network [OSTI]

Single-scattering properties of tri-axial ellipsoidal mineral dust aerosols: A database Applications and Research, Camp Spring, MD 20746, USA a r t i c l e i n f o Article history: Received 14 Optical properties Database a b s t r a c t This paper presents a user-friendly database software package

Liou, K. N.

33

BNL-65388-AB PROPERTIES OF AMMONIATED SULFATE AEROSOLS AT LOW TEMPERATURES  

E-Print Network [OSTI]

BNL-65388-AB PROPERTIES OF AMMONIATED SULFATE AEROSOLS AT LOW TEMPERATURES: WHY ARE THE MODELS SO of Energy under Contract No. DE-AC02-98CH10886. #12;PROPERTIES OF AMMONIATED SULFATE AEROSOLS AT LOW will present a study of the properties of ammoniated sulfate aerosols ((NH4)2SO4, NH4HSO4, and in- between

34

Cloud and Aerosol Properties, Precipitable Water, and Profiles of Temperature and Water Vapor from MODIS  

E-Print Network [OSTI]

Cloud and Aerosol Properties, Precipitable Water, and Profiles of Temperature and Water Vapor from such as cloud mask, atmos- pheric profiles, aerosol properties, total precipitable water, and cloud properties vapor amount, aerosol particles, and the subsequently formed clouds [9]. Barnes et al. [2] provide

Sheridan, Jennifer

35

CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES  

E-Print Network [OSTI]

CLOUD DROPLET NUCLEATION AND ITS CONNECTION TO AEROSOL PROPERTIES STEPHEN E. SCHWARTZ Environmental in cloud-free conditions and indirectly, by increasing concentratiol1S of cloud droplets thereby enhancing cloud shortwave reflectivity. These effecls are thought to be significant in the context of changes

36

Analysis of Langley optical depth data, with aerosol and gas retrievals,  

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

Analysis of Langley optical depth data, with aerosol and gas retrievals, Analysis of Langley optical depth data, with aerosol and gas retrievals, for the RSS 103 instrument in Barrow, Alaska Gianelli, Scott Columbia University - NASA/GISS Lacis, Andrew NASA/Goddard Institute for Space Studies Carlson, Barbara NASA/Goddard Institute for Space Studies Category: Aerosols Bimodal aerosol retrievals, and high-resolution retrevals of nitrogen dioxide, are performed on the Langley optical depth data from the RSS 103 device that was situated in Barrow, Alaska between March and August in 1999. The results show a higher fine mode aerosol optical depth on average than was retrieved by the RSS 102 at the SGP site. The seasonal cycle is also reversed with high values at Barrow occurring in the spring and low values in the summer. The fine mode effective radius also appears to

37

The Evolution of the Physicochemical Properties of Aerosols in the Atmosphere  

E-Print Network [OSTI]

campaign investigated the evolution of the physicochemical properties of the Asian aerosol plume after 3 to 7 days of transport. The Asian aerosol within the free troposphere exhibited a bimodal growth distribution roughly 50 percent of the time. The more...

Tomlinson, Jason

2011-02-22T23:59:59.000Z

38

Optical Properties of Secondary Organic Aerosols  

E-Print Network [OSTI]

J. H. Seinfeld, T. J. Wallington, and G. Yarwood (2002), TheJ. H. Seinfeld, T. J. Wallington, and G. Yarwood (2002), The

Kim, Hwajin

2012-01-01T23:59:59.000Z

39

Correlation Between Optical Properties And Chemical Composition...  

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

Between Optical Properties And Chemical Composition Of Sputter-deposited Germanium Cxide (GeOx) Films . Correlation Between Optical Properties And Chemical Composition Of...

40

ARM - Measurement - Hydrometeor optical properties  

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

optical properties 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 : Hydrometeor...

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Project of Aerosol Optical Depth Change in South America  

E-Print Network [OSTI]

AerosolDepth Brazil Bolivia French Guiana Suriname Guyana Venezuela Colombia Ecuador Peru Chile Argentina Suriname Guyana Venezuela Colombia Ecuador Peru Chile Argentina Paraguay Uruguay #12;Statistics of Aerosol M ean D ec 01 to 06 Mean Month AerosolDepth Brazil Bolivia French Guiana Suriname Guyana Venezuela

Frank, Thomas D.

42

REPRESENTING AEROSOL DYNAMICS AND PROPERTIES IN CHEMICAL TRANSPORT MODELS BY THE METHOD OF MOMENTS  

E-Print Network [OSTI]

understanding of the key processes that govern the aerosol size distribution: · Gas-to-particle conversion--conversion, suspensions of solid or liquid particles, are an important multi- phase system. Aerosols scatter and absorb retrospectively and prospectively for different emissions scenarios. Important aerosol properties and processes

43

Direct Aerosol Forcing Uncertainty  

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

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.

Mccomiskey, Allison

44

Climatology of aerosol optical depth in northcentral Oklahoma: 19922008  

E-Print Network [OSTI]

of aerosol models; for identification of aerosols from spe- cific events (e.g., the Central American fires Radiation Measurement Program central facility near Lamont, Oklahoma, since the fall of 1992. Most dimming; that is, the decrease in solar radiation reaching Earth's surface. Additionally, the wavelength

45

Aerosol Observing System (AOS) Handbook  

SciTech Connect (OSTI)

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 earth’s 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.

Jefferson, A

2011-01-17T23:59:59.000Z

46

Evolution of biomass burning aerosol properties from an agricultural fire in southern Africa  

E-Print Network [OSTI]

Evolution of biomass burning aerosol properties from an agricultural fire in southern Africa Steven Met Office C-130 within a distinct biomass burning plume during the Southern AFricAn Regional science, and P. R. Buseck, Evolution of biomass burning aerosol properties from an agricultural fire in southern

Highwood, Ellie

47

Intercomparison and evaluation of global aerosol microphysical properties among AeroCom models of a range of complexity  

E-Print Network [OSTI]

Many of the next generation of global climate models will include aerosol schemes which explicitly simulate the microphysical processes that determine the particle size distribution. These models enable aerosol optical ...

Ridley, David Andrew

48

Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 4.2 Comparison between the MODIS RGB image (left panel) and aerosol optical depth derived in the MODIS Deep Blue product (right panel) over the Sahara Desert on April 1, 2010. . . . . . . . . . . . . . . . . 85 xii 4.3 Comparison between.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 4.2 Comparison between the MODIS RGB image (left panel) and aerosol optical depth derived in the MODIS Deep Blue product (right panel) over the Sahara Desert on April 1, 2010. . . . . . . . . . . . . . . . . 85 xii 4.3 Comparison between...

Huang, Xin

2013-08-01T23:59:59.000Z

49

Optical properties of carbon nanotubes  

Science Journals Connector (OSTI)

Using the extended Hubbard model and sum-over-state method, we have calculated the linear polarizability ? and the third-order nonlinear polarizability ? for carbon nanotubes with finite lengths. We find that the chiral symmetry of nanotubes with finite length has a great effect on their optical properties. For example, the finite length (n,m) tubes with n-m being not a multiple of 3, will have smaller ? and much smaller ? values than other finite length tubes.

Xiangang Wan; Jinming Dong; D. Y. Xing

1998-09-15T23:59:59.000Z

50

CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan  

SciTech Connect (OSTI)

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.

Zaveri, RA; Shaw, WJ; Cziczo, DJ

2010-05-27T23:59:59.000Z

51

Aerosol radiative forcing and the accuracy of satellite aerosol optical depth retrieval  

E-Print Network [OSTI]

, New Mexico, USA Michael Mishchenko Goddard Institute for Space Studies, NASA, New York, New York, USA between t = 0.1 and t = 0.8. The Department of Energy research satellite instrument, the Multispectral [Hobbs et al., 1997]. The aerosols' direct effect involves their interaction with solar and terrestrial

52

Chemical and Physical Properties of Atmospheric Aerosols (a) A Case Study in the Unique Properties of Agricultural Aerosols (b) The Role of Chemical Composition in Ice Nucleation during the Arctic Spring  

E-Print Network [OSTI]

dataset is reported for these physical and chemical properties of agricultural aerosols appropriate for use in a site-specific emission inventory. The emission rate and transport of the aerosols are also discussed. In addition, mixing ratios of total...

Moon, Seong-Gi

53

Optical Properties and Potential Applications of Doped Semiconductor...  

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

Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Abstract:...

54

Synthesis and Optical Properties of Sulfide Nanoparticles Prepared...  

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

Optical Properties of Sulfide Nanoparticles Prepared in Dimethylsulfoxide. Synthesis and Optical Properties of Sulfide Nanoparticles Prepared in Dimethylsulfoxide. Abstract: Many...

55

ARM AOS Processing Status and Aerosol Intensive Properties VAP  

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

Andrews, and P. J. Sheridan National Oceanic and Atmospheric Administration Boulder, Colorado Abstract The Atmospheric Radiation Measurement (ARM) Aerosol Observing System (AOS)...

56

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

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

A decade long aerosol and cloud statistics and aerosol indirect effect at 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 interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We specially focused on aerosol-cloud interactions. We found a signature of indirect aerosol effect for summer data: increased aerosol index has a statistically-significant anti-correlation with mean effective radius. No

57

NFRC Interlaboratory Comparison on Optical Properties  

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

NFRC Interlaboratory Comparison on Optical Properties NFRC Interlaboratory Comparison on Optical Properties Title NFRC Interlaboratory Comparison on Optical Properties Publication Type Conference Paper LBNL Report Number LBNL-501E Year of Publication 2007 Authors Jonsson, Jacob C., and Michael D. Rubin Conference Name NFRC Conference Date Published 03/2006 Conference Location San Diego, CA Call Number LBNL-501E Abstract As part of the NFRC rating process, optical data on glazing materials is combined with other information to calculate various properties of a window product. The administrative procedure for gathering such optical data is governed by NFRC 3021, which in turn refers to NFRC 3002 and NFRC 3013 for the technical procedures by which the optical properties are determined in the solar and infrared ranges, respectively. In practice, the data is compiled by the Lawrence Berkeley National Laboratory (LBNL) and becomes part of the International Glazing Database (IGDB).

58

E-Print Network 3.0 - assessing aerosol retention Sample Search...  

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

optical properties in the vicinity of biologically active... regions of the ocean. Detection of aerosol signal associated with the ocean ecosystem will provide Source:...

59

Coherence Properties of Optical Fields  

Science Journals Connector (OSTI)

This article presents a review of coherence properties of electromagnetic fields and their measurements, with special emphasis on the optical region of the spectrum. Analyses based on both the classical and quantum theories are described. After a brief historical introduction, the elementary concepts which are frequently employed in the discussion of interference phenomena are summarized. The measure of second-order coherence is then introduced in connection with the analysis of a simple interference experiment and some of the more important second-order coherence effects are studied. Their uses in stellar interferometry and interference spectroscopy are described. Analysis of partial polarization from the standpoint of correlation theory is also outlined. The general statistical description of the field is discussed in some detail. The recently discovered universal "diagonal" representation of the density operator for free fields is also considered and it is shown how, with the help of the associated generalized phase-space distribution function, the quantum-mechanical correlation functions may be expressed in the same form as the classical ones. The sections which follow deal with the statistical properties of thermal and nonthermal light, and with the temporal and spatial coherence of blackbody radiation. Later sections, dealing with fourth- and higher-order coherence effects include a discussion of the photoelectric detection process. Among the fourth-order effects described in detail are bunching phenomena, the Hanbury Brown-Twiss effect and its application to astronomy. The article concludes with a discussion of various transient superposition effects, such as light beats and interference fringes produced by independent light beams.

L. MANDEL and E. WOLF

1965-04-01T23:59:59.000Z

60

ARM - Field Campaign - Fall 1997 Aerosol IOP  

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

Aerosol IOP Aerosol IOP 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 particularly favorable for these flights during the first and third weeks of the IOP. A secondary but important goal of this IOP was to fly cloudy-sky missions over the Central Facility to study the effect of aerosol loading on cloud microphysics, and the effect of the microphysics on cloud optical properties. The Gulfstream obtained aerosol data in support of some of the

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Influence of local waste burning on atmospheric aerosol properties in urban environment  

Science Journals Connector (OSTI)

Aerosols affect the radiative energy budget on both the regional and global scales. The wavelength-dependent aerosol optical depth (AOD) is a fundamental determinant of the amount by which extra-terrestrial incoming sunlight and outgoing terrestrial radiation are being attenuated in the atmosphere. The present study addresses the influence of local waste burning on aerosol characteristics, black carbon (BC) aerosol mass concentration and spectral solar irradiance using ground-based measurements over the tropical urban environment of Hyderabad, India. AOD has been observed to be maximum during burning days compared to normal days. Aerosol size spectra suggest bimodal distributions during pre-and post-burning periods and trimodal distributions during burning periods. Angstrom wavelength exponent estimated from spectral variation of AOD suggested dominance of accumulation mode particle loading during burning days compared to normal days. Diurnal variation of BC on normal days showed a broad nocturnal peak during ?20:00 to ?24:00 h with a maximum value of BC aerosol concentration of ?14,000 ng m?3 whereas on local waste burning days enormous increases in BC concentrations have been observed with a peak at ?60,000 ng m?3. Relative attenuation of global solar irradiance during burning days has been found to be of the order of 30% in the visible and 28% in the near-infrared regions. The results are discussed in detail in this paper.

K. Madhavi Latha; K.V.S. Badarinath

2006-01-01T23:59:59.000Z

62

Retrieval of Intensive Aerosol Properties from MFRSR observations: Partly Cloudy Cases  

SciTech Connect (OSTI)

An approach for the obtaining column intensive aerosol properties, namely the single scattering albedo (SSA) and asymmetry parameter (ASP), from the Multi-Filter Rotating Shadowband Radiometer (MFRSR) spectral observations under partly cloudy conditions is described. The approach involves the MFRSR-based aerosol retrieval for clear-sky periods and an interpolation of the retrieved column aerosol properties for cloudy periods. The observed weak diurnal variability of SSA and ASP at the surface and the close association of the surface intensive aerosol properties with their column counterparts form the basis of such interpolation. The approach is evaluated by calculating the corresponding clear-sky total, direct and diffuse fluxes at five wavelengths (415, 500, 615, 673 and 870 nm) and compare them with the observed fluxes. The aerosol properties provided by this approach are applied for (i) an examination of the statistical relationship between spectral (visible spectral range) and broadband values of the total normalized cloud radiative forcing and (ii) an estimation of the fractional sky cover. Data collected during 13 days with single-layer cumulus clouds observed at U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site during summer 2007 are applied to illustrate the performance and application of this approach.

Kassianov, Evgueni I.; Barnard, James C.; Berg, Larry K.; Flynn, Connor J.; Long, Charles N.

2010-09-30T23:59:59.000Z

63

Structure, Morphology, and Optical Properties of Amorphous and...  

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

Morphology, and Optical Properties of Amorphous and Nanocrystalline Gallium Oxide Thin Films. Structure, Morphology, and Optical Properties of Amorphous and Nanocrystalline Gallium...

64

Simultaneous determination of aerosol optical thickness and exponent of Junge power law from satellite measurements of two near-infrared bands over the ocean  

Science Journals Connector (OSTI)

An iterative algorithm is presented in this study for simultaneous determination of both the aerosol optical thickness and the exponent of the Junge power law from the total...

Xu, Qingshan; Wei, Heli; Rao, Ruizhong; Hu, Huanling

2007-01-01T23:59:59.000Z

65

Factors influencing the microphysics and radiative properties of liquid-dominated Arctic clouds: insight from observations of aerosol and clouds during ISDAC  

SciTech Connect (OSTI)

Aircraft measurements during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 are used to investigate aerosol indirect effects in Arctic clouds. Two aerosol-cloud regimes are considered in this analysis: single-layer stratocumulus cloud with below-cloud aerosol concentrations (N{sub a}) below 300 cm{sup -3} on April 8 and April 26-27 (clean cases); and inhomogeneous layered cloud with N{sub a} > 500 cm{sup -3} below cloud base on April 19-20, concurrent with a biomass burning episode (polluted cases). Vertical profiles through cloud in each regime are used to determine average cloud microphysical and optical properties. Positive correlations between the cloud droplet effective radius (Re) and cloud optical depth ({tau}) are observed for both clean and polluted cases, which are characteristic of optically-thin, non-precipitating clouds. Average Re values for each case are {approx} 6.2 {mu}m, despite significantly higher droplet number concentrations (Nd) in the polluted cases. The apparent independence of Re and Nd simplifies the description of indirect effects, such that {tau} and the cloud albedo (A) can be described by relatively simple functions of the cloud liquid water path. Adiabatic cloud parcel model simulations show that the marked differences in Na between the regimes account largely for differences in droplet activation, but that the properties of precursor aerosol also play a role, particularly for polluted cases where competition for vapour amongst the more numerous particles limits activation to larger and/or more hygroscopic particles. The similarity of Re for clean and polluted cases is attributed to compensating droplet growth processes for different initial droplet size distributions.

Earle, Michael; Liu, Peter S.; Strapp, J. Walter; Zelenyuk, Alla; Imre, D.; McFarquhar, Greg; Shantz, Nicole C.; Leaitch, W. R.

2011-11-04T23:59:59.000Z

66

Laboratory investigation of chemical and physical properties of soot-containing aerosols  

E-Print Network [OSTI]

SO4-coated soot aerosols; (3) effect of H2SO4 coating on scattering and extinction properties of soot particles. A low-pressure laminar-flow reactor, coupled to ion driftchemical ionization mass spectrometry (ID-CIMS) detection, is used to study...

Zhang, Dan

2006-08-16T23:59:59.000Z

67

The seasonality of aerosol properties in Big Bend National Park  

E-Print Network [OSTI]

growth cycle present in the daily averaged 32 Day (December 2003) Dp (um) Day (December 2003) Dp (um) Day (January 2004) Dp (um) Day (January 2004) Dp (um) Day (June 2003) Dp (um) Day (June 2003) Dp (um) Day (April 2003) Dp (um) Day (April 2003) Dp... (um) Day (December 2003) Dp (um) Day (December 2003) Dp (um) Day (January 2004) Dp (um) Day (January 2004) Dp (um) Day (June 2003) Dp (um) Day (June 2003) Dp (um) Day (April 2003) Dp (um) Day (April 2003) Dp (um) Fig. 12. Seasonal aerosol number...

Allen, Christopher Lee

2007-04-25T23:59:59.000Z

68

E-Print Network 3.0 - airborne aerosol prediction Sample Search...  

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

profiles of aerosol extinction and optical depth Evaluate predictions from aerosol transport... aerosol measurements. Comparison of AOT ... Source: Brookhaven National...

69

Effects of internal mixing and aggregate morphology on optical properties  

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

Effects of internal mixing and aggregate morphology on optical properties Effects of internal mixing and aggregate morphology on optical properties of black carbon using a discrete dipole approximation model Title Effects of internal mixing and aggregate morphology on optical properties of black carbon using a discrete dipole approximation model Publication Type Journal Article Year of Publication 2013 Authors Scarnato, B., S. Vahidinia, D. T. Richard, and Thomas W. Kirchstetter Journal Atmospheric Chemistry and Physics Volume 12 Pagination 26401-26434 Abstract According to recent studies, internal mixing of black carbon (BC) with other aerosol materials in the atmosphere alters its aggregate shape, absorption of solar radiation, and radiative forcing. These mixing state effects are not yet fully understood. In this study, we characterize the morphology and mixing state of bare BC and BC internally mixed with sodium chloride (NaCl) using electron microscopy and examine the sensitivity of optical properties to BC mixing state and aggregate morphology using a discrete dipole approximation model (DDSCAT). DDSCAT predicts a higher mass absorption coefficient, lower single scattering albedo (SSA), and higher absorption Angstrom exponent (AAE) for bare BC aggregates that are lacy rather than compact. Predicted values of SSA at 550 nm range between 0.18 and 0.27 for lacy and compact aggregates, respectively, in agreement with reported experimental values of 0.25 ± 0.05. The variation in absorption with wavelength does not adhere precisely to a power law relationship over the 200 to 1000 nm range. Consequently, AAE values depend on the wavelength region over which they are computed. In the 300 to 550 nm range, AAE values ranged in this study from 0.70 for compact to 0.95 for lacy aggregates. The SSA of BC internally mixed with NaCl (100-300 nm in radius) is higher than for bare BC and increases with the embedding in the NaCl. Internally mixed BC SSA values decrease in the 200-400 nm wavelength range, a feature also common to the optical properties of dust and organics. Linear polarization features are also predicted in DDSCAT and are dependent on particle morphology. The bare BC (with a radius of 80 nm) presents in the linear polarization a bell shape feature, which is a characteristic of the Rayleigh regime (for particles smaller than the wavelength of incident radiation). When BC is internally mixed with NaCl (100-300 nm in radius), strong depolarization features for near-VIS incident radiation are evident, such as a decrease in the intensity and multiple modes at different angles corresponding to different mixing states.

70

Optical properties of ??-CoAl  

Science Journals Connector (OSTI)

The optical absorptance of ??-CoAl in the (0.1-2.5)-eV region was measured and analyzed by the Kramers-Kronig method. The optical conductivity shows interband features beginning below 0.1 eV, with several structures below 2 eV. These structures agree with those calculated from the energy bands of Moruzzi, Williams, and Gelatt. The experimentally observed systematics in CoAl and NiAl confirm our previous interpretation of the spectra of ??-NiAl, and disagree with other experimental and theoretical attempts to understand the optical properties of these compounds.

D. W Lynch; B. R. Boeke; D. J. Peterman

1982-04-15T23:59:59.000Z

71

Optical Properties of a ?-Vacuum  

E-Print Network [OSTI]

Chern-Simons (CS) forms generalize the minimal coupling between gauge potentials and point charges, to sources represented by charged extended objects (branes). The simplest example of such a CS-brane coupling is a domain wall coupled to the electromagnetic CS three-form. This describes a topologically charged interface where the CS form AdA is supported, separating two three-dimensional spatial regions in 3+1 spacetime. Electrodynamics at either side of the brane is described by the same Maxwell's equations, but those two regions have different vacua, characterized by a different value of the \\theta-parameter multiplying the Pontryagin form F ^ F. The \\theta-term is the abelian version of the concept introduced by 't Hooft for the resolution of the U(1) problem in QCD. We point out that CS-generalized classical electrodynamics shows new phenomena when two neighboring regions with different \\theta-vacua are present. These topological effects result from surface effects induced by the boundary and we explore the consequences of such boundary effects for the propagation of the electromagnetic field in Maxwell theory. Several features, including optical and electrostatic/magnetostatic responses, which may be observable in condensed matter systems, like topological insulators, are discussed.

Luis Huerta; Jorge Zanelli

2012-02-10T23:59:59.000Z

72

Incorporation of Aerosol Optical Properties into Climate Models  

E-Print Network [OSTI]

. Measured Annual Lightning Flash Rate Data from NASA LIS/OTD Science Team Model (4ox5o resolution) calculates lightning by accounting for size-resolved bounceoffs and charge separation in clouds. Results

73

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

SciTech Connect (OSTI)

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.

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

2012-07-25T23:59:59.000Z

74

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

SciTech Connect (OSTI)

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.

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

2010-10-01T23:59:59.000Z

75

Mixed Metal Films with Switchable Optical Properties  

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

Mixed Metal Films with Switchable Optical Properties Mixed Metal Films with Switchable Optical Properties Title Mixed Metal Films with Switchable Optical Properties Publication Type Journal Article LBNL Report Number LBNL-49043 Year of Publication 2001 Authors Richardson, Thomas J., Jonathan L. Slack, Baker Farangis, and Michael D. Rubin Journal Applied Physics Letters Volume 80 Pagination 1349-1351 Call Number LBNL-49043 Abstract Thin, Pd-capped metallic films containing magnesium and first row transition metals (Mn, Fe, Co) switch reversibly from their initial reflecting state to visually transparent states when exposed to gaseous hydrogen or following reduction cathodic polarization in an alkaline electrolyte. Reversion to the reflecting state is achieved by exposure to air or by anodic polarization. The films were prepared by co-sputtering from one magnesium target and one manganese, iron, or cobalt target. Both the dynamic optical switching range and the speed of the transition depend on the magnesium-transition metal ratio. Infrared spectra of films in the transparent, hydrided (deuterided) states support the presence of the intermetallic hydride phases Mg3MnH7, Mg2FeH6, and Mg2CoH5.

76

Retrieval of Aerosol Optical Depth in Vicinity of Broken Clouds from Reflectance Ratios: Case Study  

SciTech Connect (OSTI)

A recently developed reflectance ratio (RR) method for the retrieval of aerosol optical depth (AOD) is evaluated using extensive airborne and ground-based data sets collected during the Cloud and Land Surface Interaction Campaign (CLASIC) and the Cumulus Humilis Aerosol Processing Study (CHAPS), which took place in June 2007 over the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains site. A detailed case study is performed for a field of single-layer shallow cumuli observed on June 12, 2007. The RR method is applied to retrieve the spectral values of AOD from the reflectance ratios measured by the MODIS Airborne Simulator (MAS) for two pairs of wavelengths (660 and 470 nm and 870 and 470 nm) collected at a spatial resolution of 0.05 km. The retrieval is compared with an independent AOD estimate from three ground-based Multi-filter Rotating Shadowband Radiometers (MFRSRs). The interpolation algorithm that is used to project MFRSR point measurements onto the aircraft flight tracks is tested using AOD derived from NASA Langley High Spectral Resolution Lidar (HSRL). The RR AOD estimates are in a good agreement (within 5%) with the MFRSR-derived AOD values for the 660-nm wavelength. The AODs obtained from MAS reflectance ratios overestimate those derived from MFRSR measurements by 15-30% for the 470-nm wavelength and underestimate the 870-nm AOD by the same amount.

Kassianov, Evgueni I.; Ovchinnikov, Mikhail; Berg, Larry K.; McFarlane, Sally A.; Flynn, Connor J.; Ferrare, Richard; Hostetler, Chris A.; Alexandrov, Mikhail

2010-10-06T23:59:59.000Z

77

Do Diurnal Aerosol Changes Affect Daily Average Radiative Forcing?  

SciTech Connect (OSTI)

Strong diurnal variability of aerosol has been observed frequently for many urban/industrial regions. How this variability may alter the direct aerosol radiative forcing (DARF), however, is largely unknown. To quantify changes in the time-averaged DARF, we perform an assessment of 29 days of high temporal resolution ground-based data collected during the Two-Column Aerosol Project (TCAP) on Cape Cod, which is downwind of metropolitan areas. We demonstrate that strong diurnal changes of aerosol loading (about 20% on average) have a negligible impact on the 24-h average DARF, when daily averaged optical properties are used to find this quantity. However, when there is a sparse temporal sampling of aerosol properties, which may preclude the calculation of daily averaged optical properties, large errors (up to 100%) in the computed DARF may occur. We describe a simple way of reducing these errors, which suggests the minimal temporal sampling needed to accurately find the forcing.

Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Michalsky, Joseph J.; Lantz, K.; Hodges, G. B.

2013-06-17T23:59:59.000Z

78

Optical properties of LiF  

Science Journals Connector (OSTI)

In this paper, we examine the optical properties of LiF. The fundamental calculations performed are a self-consistent Hartree-Fock band-structure calculation. As has been found previously, such a calculation has substantial errors when compared with experiment. Correlation corrections are needed and are included by means of the electronic-polaron method. The usual electronic polaron is extended to include short-range polarization corrections which the usual model neglects but which are peculiarly large for LiF. The energy bands are evaluated directly by the linear-combination-of-local-basis-functions method along with the crystal wave functions for 89 points in the irreducible wedge of the first Brillouin zone. Using these results and the Lemann-Taut interpolation scheme the density of states, the joint density of states, and the imaginary part of the dielectric function are computed. These results which neglect the formation of excitons and "plasmons" are in poor agreement with experiment. The effect of the exciton formation is included by a Koster-Slater one-band—one-site calculation. We find that the inclusion of exciton effects substantially improves the level of agreement with experiment. This is in direct contrast with recent work of Menzel et al. in which energy-band theory alone is found to account for the optical properties of LiF. This disagreement is discussed in detail.

Daniel J. Mickish; A. Barry Kunz; T. C. Collins

1974-05-15T23:59:59.000Z

79

Ultrafast nonlinear optical properties of passive and active semiconductor devices  

E-Print Network [OSTI]

Nonlinear optical properties and ultrafast carrier dynamics of slab-coupled optical waveguide amplifiers, silicon nanowaveguides, and III-V semiconductor saturable Bragg reflectors are studied. The limits imposed by two ...

Motamedi, Ali Reza

2011-01-01T23:59:59.000Z

80

Retrieval of Aerosol Optical Depth in Vicinity of Broken Clouds from Reflectance Ratios: Sensitivity Study  

SciTech Connect (OSTI)

We conducted a sensitivity study to better understand the potential of a new method for retrieving aerosol optical depth (AOD) under partly cloudy conditions. This method exploits reflectance ratios in the visible spectral range and provides an effective way to avoid three-dimensional (3D) cloud effects. The sensitivity study is performed for different observational conditions and random errors in input data. The results of the sensitivity study suggest that this ratio method has the ability to detect clear pixels even in close proximity to clouds. Such detection does not require a statistical analysis of the two-dimensional (2D) horizontal distribution of reflected solar radiation, and thus it could be customized for operational retrievals. In comparison with previously suggested approaches, the ratio method has the capability to increase the "harvest" of clear pixels. Similar to the traditional Independent Pixel Approximation (IPA), the ratio method has a low computational cost for retrieving AOD. In contrast to the IPA method, the ratio method provides much more accurate estimations of the AOD values under broken cloud conditions: pixel-based and domain-averaged estimations of errors in AOD are about 25% and 10%, respectively. Finally, both the ratio-based cloud screening and the accuracy of domain-averaged ratio-based AOD values do not suffer greatly when 5% random errors are introduced in the reflectances.

Kassianov, Evgueni I.; Ovtchinnikov, Mikhail; Berg, Larry K.; McFarlane, Sally A.; Flynn, Connor J.

2009-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Aerosol Radiative Effects and Single-Scattering Properties in the Tropical Western Pacific  

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

Effects and Single-Scattering Properties Effects and Single-Scattering Properties in the Tropical Western Pacific A. M. Vogelmann and P. J. Flatau Center for Atmospheric Sciences Scripps 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 P. J. Flatau University Corporation for Atmospheric Research Naval Research Laboratory Monterey, California K. M. Markowicz Institute of Geophysics University of Warsaw Warsaw, Poland Introduction The Atmospheric Radiation Measurement (ARM) Tropical Western Pacific (TWP) sites are downwind from Southeast Asia where biomass burning occurs and can advect over the tropical warm pool. Previous research (Vogelmann 2001, 2002, 2003) indicates that aerosol forcing was particularly large

82

Optical properties of cooled Rhodamine B in ethanol  

Science Journals Connector (OSTI)

The optical properties of an organic laser dye luminophor, Rhodamine B in ethanol, were investigated at both high and low concentrations as a function of temperature. At high...

Ali, M A; Moghaddasi, J; Ahmed, S A

1991-01-01T23:59:59.000Z

83

Optical and electrochemical properties of hydrogen-bondedphenol...  

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

Optical and electrochemical properties of hydrogen-bonded phenol-pyrrolidino60fullerenes Authors: Moore, G. F., Megiatto, J. D., Hambourger, M., Gervaldo, M., Kodis, G., Moore,...

84

Effects of internal mixing and aggregate morphology on optical properties  

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

3 3 Authors Scarnato, Barbara V., Sanaz Vahidinia, D. T. Richard, and Thomas W. Kirchstetter Journal Atmospheric Chemistry and Physics Volume 13 Start Page 5089 Issue 10 Pagination 5089 - 5101 Date Published 05/2013 Abstract According to recent studies, internal mixing of black carbon (BC) with other aerosol materials in the atmosphere alters its aggregate shape, absorption of solar radiation, and radiative forcing. These mixing state effects are not yet fully understood. In this study, we characterize the morphology and mixing state of bare BC and BC internally mixed with sodium chloride (NaCl) using electron microscopy and examine the sensitivity of optical properties to BC mixing state and aggregate morphology using a discrete dipole approximation model (DDSCAT). DDSCAT is flexible in simulating the geometry and refractive index of particle aggregates. DDSCAT predicts a higher mass absorption coefficient (MAC), lower single scattering albedo (SSA), and higher absorption Angstrom exponent (AAE) for bare BC aggregates that are lacy rather than compact. Predicted values of SSA at 550 nm range between 0.16 and 0.27 for lacy and compact aggregates, respectively, in agreement with reported experimental values of 0.25 ± 0.05. The variation in absorption with wavelength does not adhere precisely to a power law relationship over the 200 to 1000 nm range. Consequently, AAE values depend on the wavelength region over which they are computed. The MAC of BC (averaged over the 200-1000 nm range) is amplified when internally mixed with NaCl (100-300 nm in radius) by factors ranging from 1.0 for lacy BC aggregates partially immersed in NaCl to 2.2 for compact BC aggregates fully immersed in NaCl. The SSA of BC internally mixed with NaCl is higher than for bare BC and increases with the embedding in the NaCl. Internally mixed BC SSA values decrease in the 200-400 nm wavelength range, a feature also common to the optical properties of dust and organics. Linear polarization features are also predicted in DDSCAT and are dependent on particle size and morphology.

85

An Automated Method of MFRSR Calibration for Aerosol Optical Depth Analysis with Application to an Asian Dust Outbreak over the United States  

Science Journals Connector (OSTI)

Over the past decade, networks of Multifilter Rotating Shadowband Radiometers (MFRSR) and automated sun photometers have been established in the United States to monitor aerosol properties. The MFRSR alternately measures diffuse and global ...

John A. Augustine; Christopher R. Cornwall; Gary B. Hodges; Charles N. Long; Carlos I. Medina; John J. DeLuisi

2003-02-01T23:59:59.000Z

86

STABILITY PROPERTIES OF LIGHT PROPAGATING IN FIBER OPTICS  

E-Print Network [OSTI]

STABILITY PROPERTIES OF LIGHT PROPAGATING IN FIBER OPTICS ST´EPHANE LAFORTUNE Summary The study is crucial in applications such as lasers and optical fibers. In this proposal I will focus on a model of fiber optics: the Manakov system. This system consists of two differential equations, that is two

Kasman, Alex

87

Dynamic optical properties in graphene: Length versus velocity gauge  

SciTech Connect (OSTI)

The dynamic optical properties of graphene are theoretically investigated in both length gauge and velocity gauge in the presence of ultrafast optical radiation field. The two gauges present different results of dynamic photo-induced carriers and optical conductance due to distinct dependencies on electric field and non-resonant optical absorption, while the two gauges give identical results in the steady state time. It shows that the choice of gauge affects evidently the dynamic optical properties of graphene. The velocity gauge represents an outcome of a real physical experiment.

Dong, H. M.; Han, K., E-mail: han6409@263.net [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Xu, W. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Physics, Yunnan University, Kunming 650091 (China)

2014-02-14T23:59:59.000Z

88

Preparation, optical and non-linear optical power limiting properties of Cu, CuNi nanowires  

SciTech Connect (OSTI)

Metallic nanowires show excellent Plasmon absorption which is tunable based on its aspect ratio and alloying nature. We prepared Cu and CuNi metallic nanowires and studied its optical and nonlinear optical behavior. Optical properties of nanowires are theoretically explained using Gans theory. Nonlinear optical behavior is studied using a single beam open aperture z-scan method with the use of 5?ns Nd: YAG laser. Optical limiting is found to arise from two-photon absorption.

Udayabhaskar, R.; Karthikeyan, B., E-mail: bkarthik@nitt.edu [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015 (India); Ollakkan, Muhamed Shafi [Light and Matter Physics Group, Raman Research Institute, Bangalore 560 080 (India)] [Light and Matter Physics Group, Raman Research Institute, Bangalore 560 080 (India)

2014-01-06T23:59:59.000Z

89

1 - Fundamental optical properties of carbon nanotubes and graphene  

Science Journals Connector (OSTI)

Abstract: The fundamental electronic states and optical properties of single-walled carbon nanotubes are briefly explained in this chapter. Moreover, the novel optical properties of carbon nanotubes revealed by advanced laser spectroscopy (single-nanotube spectroscopy and time-resolved spectroscopy) are introduced. Due to the enhanced Coulomb interaction, the optically generated electron-hole pair forms a strongly bound ‘exciton’ state, analogous to the hydrogen-like state in the carbon nanotubes. The striking features of excitons in the carbon nanotube, such as singlet-dark states and triplet states, which dominate the optical properties, are described in this chapter.

K. Matsuda

2013-01-01T23:59:59.000Z

90

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)

An Observed Signature of Aerosol Effect on Cloud Droplet Radii from a 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 1993. Diurnal, monthly, seasonal and interannual variability of aerosol (optical depth and Angstrom coefficient) and cloud (optical depth and effective radius) have been analyzed. We have correlated an "aerosol index" computed from clear-sky observations of MFRSR with cloud droplet mean effective radius to study the

91

ARM - Field Campaign - 2007 Cumulus Humilis Aerosol Process Study (CHAPS)  

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

7 Cumulus Humilis Aerosol Process Study (CHAPS) 7 Cumulus Humilis Aerosol Process Study (CHAPS) Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2007 Cumulus Humilis Aerosol Process Study (CHAPS) 2007.06.04 - 2007.06.25 Lead Scientist : Carl Berkowitz For data sets, see below. Description The primary goal of this campaign was to characterize and contrast freshly emitted aerosols above, within and below fields of cumulus humilis (or fair-weather cumulus, FWC) and to use these observations to address how below-cloud and above-cloud aerosol optical and cloud nucleating properties differ downwind of a mid-size city relative to similar aerosols in air less affected by emissions. The observations from this campaign can also be used to aid in the development and evaluation of parameterizations of the

92

The optical properties of bismuth nanowires  

E-Print Network [OSTI]

The optical absorption of bismuth nanowires in the energy (wavenumber) range of 600 - 4000cm-1 is studied. Optical reflection and transmission spectra reveal that bismuth nanowires have a large and intense absorption peak ...

Black, Marcie R. (Marcie Rochelle)

2003-01-01T23:59:59.000Z

93

The Two-Column Aerosol Project (TCAP) Science Plan  

SciTech Connect (OSTI)

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.

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

2011-07-27T23:59:59.000Z

94

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

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

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.

Sedlacek, Art

95

BNL | Two-Column Aerosol Program (TCAP)  

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

Two-Column Aerosol Project (TCAP) Two-Column Aerosol Project (TCAP) There remain many key knowledge gaps despite advances in the scientific understanding of how aerosols and clouds evolve and affect climate. Many climatically important processes depend on particles that undergo continuous changes within a size range spanning a few nanometers to a few microns, and with compositions that consist of a variety of carbonaceous materials, soluble inorganic salts and acids and insoluble mineral dust. Primary particles, which are externally-mixed when emitted, are subject to coagulation and chemical changes associated with the condensation of semi-volatile gases to their surface resulting in a spectrum of compositions or mixing-states with a range of climate-affecting optical and hygroscopic properties. The numerical treatments of aerosol transformation

96

Aerosol Best Estimate Value-Added Product  

SciTech Connect (OSTI)

The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.

Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C

2012-07-19T23:59:59.000Z

97

OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES  

SciTech Connect (OSTI)

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 materials. Linear, including absorption and luminescence, and nonlinear optical as well as dynamic properties of semiconductor nanoparticles are discussed with focus on their dependence on particle size, shape, and surface characteristics. Both doped and undoped semiconductor nanomaterials are highlighted and contrasted to illustrate the use of doping to effectively alter and probe nanomaterial properties. Some emerging applications of optical nanomaterials are discussed towards the end of the chapter, including solar energy conversion, optical sensing of chemicals and biochemicals, solid state lighting, photocatalysis, and photoelectrochemistry.

Grant, C D; Zhang, J Z

2007-09-28T23:59:59.000Z

98

Optical properties of nanostructured silicon-rich silicon dioxide  

E-Print Network [OSTI]

We have conducted a study of the optical properties of sputtered silicon-rich silicon dioxide (SRO) thin films with specific application for the fabrication of erbium-doped waveguide amplifiers and lasers, polarization ...

Stolfi, Michael Anthony

2006-01-01T23:59:59.000Z

99

Dust aerosol, clouds, and the atmospheric optical depth record over 5 Mars years of the Mars Exploration Rover mission  

E-Print Network [OSTI]

Dust aerosol plays a fundamental role in the behavior and evolution of the Martian atmosphere. The first five Mars years of Mars Exploration Rover data provide an unprecedented record of the dust load at two sites. This record is useful for characterization of the atmosphere at the sites and as ground truth for orbital observations. Atmospheric extinction optical depths have been derived from solar images after calibration and correction for time-varying dust that has accumulated on the camera windows. The record includes local, regional, and globally extensive dust storms. Comparison with contemporaneous thermal infrared data suggests significant variation in the size of the dust aerosols, with a 1 {\\mu}m effective radius during northern summer and a 2 {\\mu}m effective radius at the onset of a dust lifting event. The solar longitude (LS) 20-136{\\deg} period is also characterized by the presence of cirriform clouds at the Opportunity site, especially near LS=50 and 115{\\deg}. In addition to water ice clouds, ...

Lemmon, Mark T; Bell, James F; Smith, Michael D; Cantor, Bruce A; Smith, Peter H

2014-01-01T23:59:59.000Z

100

Modeling aerosols and their interactions with shallow cumuli during the 2007 CHAPS field study  

SciTech Connect (OSTI)

The Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is used to simulate relationships between aerosols and clouds in the vicinity of Oklahoma City during the June 2007 Cumulus Humilis Aerosol Processing Study (CHAPS). The regional scale simulation completed using 2 km horizontal grid spacing evaluates four important relationships between aerosols and shallow cumulus clouds observed during CHAPS. First, the model reproduces the trends of higher nitrate volume fractions in cloud droplet residuals compared to interstitial non-activated aerosols, as measured using the Aerosol Mass Spectrometer. Comparing simulations with cloud chemistry turned on and off, we show that nitric acid vapor uptake by cloud droplets explains the higher nitrate content of cloud droplet residuals. Second, as documented using an offline code, both aerosol water and other inorganics (OIN), which are related to dust and crustal emissions, significantly affect predicted aerosol optical properties. Reducing the OIN content of wet aerosols by 50% significantly improves agreement of model predictions with measurements of aerosol optical properties. Third, the simulated hygroscopicity of aerosols is too high as compared to their hygroscopicity derived from cloud condensation nuclei and particle size distribution measurements, indicating uncertainties associated with simulating size-dependent chemical composition and treatment of aerosol mixing state within the model. Fourth, the model reasonably represents the observations of the first aerosol indirect effect where pollutants in the vicinity of Oklahoma City increase cloud droplet number concentrations and decrease the droplet effective radius. While previous studies have often focused on cloud-aerosol interactions in stratiform and deep convective clouds, this study highlights the ability of regional-scale models to represent some of the important aspects of cloud-aerosol interactions associated with fields of short-lived shallow cumuli.

Shrivastava, ManishKumar B.; Berg, Larry K.; Fast, Jerome D.; Easter, Richard C.; Laskin, Alexander; Chapman, Elaine G.; Gustafson, William I.; Liu, Ying; Berkowitz, Carl M.

2013-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Optical Properties and Orientation in Polyethylene Blown Films  

E-Print Network [OSTI]

Optical Properties and Orientation in Polyethylene Blown Films AYUSH BAFNA,1 GREGORY BEAUCAGE,1 properties of blown poly- ethylene films. Two types of blown polyethylene films of similar degrees of crystallinity were made from (1) single-site-catalyst high-density polyethylene (HDPE; STAR ) and (2) Ziegler

Beaucage, Gregory

102

Development and Characterization of a Thermodenuder for Aerosol Volatility Measurements  

SciTech Connect (OSTI)

This SBIR Phase I project addressed the critical need for improved characterization of carbonaceous aerosol species in the atmosphere. The proposed work focused on the development of a thermodenuder (TD) system capable of systematically measuring volatility profiles of primary and secondary organic aerosol species and providing insight into the effects of absorbing and nonabsorbing organic coatings on particle absorption properties. This work provided the fundamental framework for the generation of essential information needed for improved predictions of ambient aerosol loadings and radiative properties by atmospheric chemistry models. As part of this work, Aerodyne Research, Inc. (ARI) continued to develop and test, with the final objective of commercialization, an improved thermodenuder system that can be used in series with any aerosol instrument or suite of instruments (e.g., aerosol mass spectrometers-AMS, scanning mobility particle sizers-SMPS, photoacoustic absorption spectrometers-PAS, etc.) to obtain aerosol chemical, physical, and optical properties as a function of particle volatility. In particular, we provided the proof of concept for the direct coupling of our improved TD design with a full microphysical model to obtain volatility profiles for different organic aerosol components and to allow for meaningful comparisons between different TD-derived aerosol measurements. In a TD, particles are passed through a heated zone and a denuding (activated charcoal) zone to remove semi-volatile material. Changes in particle size, number concentration, optical absorption, and chemical composition are subsequently detected with aerosol instrumentation. The aerosol volatility profiles provided by the TD will strengthen organic aerosol emission inventories, provide further insight into secondary aerosol formation mechanisms, and provide an important measure of particle absorption (including brown carbon contributions and identification, and absorption enhancements due to coatings on soot particles). The successfully completed Phase I project included construction of a prototype design for the TD with detailed physical modeling, testing with laboratory and ambient aerosol particles, and the initiation of a detailed microphysical model of the aerosol particles passing through the TD to extract vapor pressure distributions. The objective of the microphysical model is to derive vapor pressure distributions (i.e. vapor pressure ranges, including single chemical compounds, mixtures of known compounds, and complex ‘real-world’ aerosols, such as SOA, and soot particles with absorbing and nonabsorbing coatings) from TD measurements of changes in particle size, mass, and chemical composition for known TD temperatures and flow rates (i.e. residence times). The proposed Phase II project was designed to optimize several TD systems for different instrument applications and to combine the hardware and modeling into a robust package for commercial sales.

Dr. Timothy Onasch

2009-09-09T23:59:59.000Z

103

Tunable optical properties of multilayers black phosphorus  

E-Print Network [OSTI]

We calculated the optical conductivity tensor of multilayers black phosphorus using the Kubo formula within an effective low-energy Hamiltonian. The optical absorption spectra of multilayers black phosphorus are shown to vary sensitively with thickness, doping, and light polarization. In conjunction with experimental spectra obtained from infrared absorption spectroscopy, we discuss the role of interband coupling and disorder on the observed anisotropic absorption spectra. Multilayers black phosphorus might offer attractive alternatives to narrow gap compound semiconductors for optoelectronics across mid- to near-infrared frequencies.

Low, Tony; Carvalho, A; Jiang, Yongjin; Wang, Han; Xia, Fengnian; Neto, A H Castro

2014-01-01T23:59:59.000Z

104

Distinct optical properties of relativistically degenerate matter  

SciTech Connect (OSTI)

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.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, Tabriz 51745-406 (Iran, Islamic Republic of); International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, Bochum D-44780 (Germany)

2014-06-15T23:59:59.000Z

105

ARM - Field Campaign - MArine Stratus Radiation Aerosol and Drizzle  

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

govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP govCampaignsMArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP Campaign Links Science Plan AMF Point Reyes Website AMF Point Reyes Data Plots Related Campaigns MASRAD: Pt. Reyes Stratus Cloud and Drizzle Study 2005.07.07, Coulter, AMF MASRAD: Cloud Condensate Nuclei Chemistry Measurements 2005.07.01, Berkowitz, AMF MASRAD - Aerosol Optical Properties 2005.06.29, Strawa, AMF MASRAD:Sub-Micron Aerosol Measurements 2005.06.20, Wang, AMF MASRAD: Cloud Study from the 2NFOV at Pt. Reyes Field Campaign 2005.06.02, Wiscombe, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : MArine Stratus Radiation Aerosol and Drizzle (MASRAD) IOP 2005.03.14 - 2005.09.14 Website : http://www.arm.gov/sites/amf/pye/ Lead Scientist : Mark Miller

106

The Optical Properties of Some Petroleum Products  

E-Print Network [OSTI]

,in the course of time, under the influence of catalytic agents, may give rise to the dextro- and laevorotatory substances which cause the activity of petroleum. 33 It was Rakusin who first observed that a greater rotation was given by the naphthenic acids... derived from the residues of Bussian petroleum refining than by the petroleum itself. Finding that some naphthenic acids derived from kerosene gave a dextrorotation of +0.55° (sacch.0 in 200 mm. tube), he concluded that the optical activity...

Humphrey, Irvin W.

1913-05-15T23:59:59.000Z

107

Nonlinear optical properties of the magnetized QED Vacuum  

E-Print Network [OSTI]

New processes associated with the nonlinear optical properties of the electromagnetic vacuum, as predicted by quantum electrodynamics are described. We consider the presence of a static and a rotating magnetic field. The cases of harmonic generation and two different types of sideband cascades are considered. First order and second order effects with respect to the external magnetic field are discussed in detail. Possible experimental configurations using ultra-intense lasers are compared with the alternative use of cw lasers in stable optical cavities.

J. T. Mendonca

2007-04-12T23:59:59.000Z

108

Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic...  

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

Aerosol Campaign: The Impact of Arctic Aerosols on Clouds . Abstract: A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic...

109

Artificial neural network method for determining optical properties from double-integrating-spheres measurements  

Science Journals Connector (OSTI)

Accurate measurement of the optical properties of biological tissue is very important for optical diagnosis and therapeutics. An artificial neural network (ANN)-based inverse...

Li, Chenxi; Zhao, Huijuan; Wang, Qiuyin; Xu, Kexin

2010-01-01T23:59:59.000Z

110

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

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

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....

111

Band structure and optical properties of isolated and bundled nanotubes  

E-Print Network [OSTI]

Band structure and optical properties of isolated and bundled nanotubes S. Reich , C. Thomsen , P of isolated and bundled single-walled nanotubes by ab initio calculations. Curvature effects on the electronic states depend on the chirality of the nanotube; the strongest deviations from the zone

Nabben, Reinhard

112

BAND STRUCTURE AND OPTICAL PROPERTIES OF MAGNESIUM FLUORIDE  

E-Print Network [OSTI]

595 BAND STRUCTURE AND OPTICAL PROPERTIES OF MAGNESIUM FLUORIDE C. JOUANIN, J. P. ALBERT and C'autres transitions expéri- mentales. Abstract. 2014 The electronic band structure of magnesium fluoride is calculated, only some qualitative investigations exist for the calcium and magnesium fluorides [1, 2]. This lack

Paris-Sud XI, Université de

113

E-Print Network 3.0 - aerosol microphysical characteristics Sample...  

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

new particle formation, aerosol microphysical evolution, three-dimensional transport, and wet... of aerosol microphysical properties. Some of ... Source: Brookhaven...

114

Optical properties of fly ash. Volume 2, Final report  

SciTech Connect (OSTI)

Research performed under this contract was divided into four tasks under the following headings: Task 1, Characterization of fly ash; Task 2, Measurements of the optical constants of slags; Task 3, Calculations of the radiant properties of fly ash dispersions; and Task 4, Measurements of the radiant properties of fly ash dispersions. Tasks 1 and 4 constituted the Ph.D. research topic of Sarbajit Ghosal, while Tasks 2 and 3 constituted the Ph.D. research topic of Jon Ebert. Together their doctoral dissertations give a complete account of the work performed. This final report, issued in two volumes consists of an executive summary of the whole program followed by the dissertation of Ghosal and Ebert. Volume 2 contains the dissertation of Ebert which covers the measurements of the optical constants of slags, and calculations of the radiant properties of fly ash dispersions. A list of publications and conference presentations resulting from the work is also included.

Self, S.A.

1994-12-01T23:59:59.000Z

115

Equation of state and optical properties of warm dense helium  

Science Journals Connector (OSTI)

We investigate the physical properties of warm dense helium under the conditions found in the atmospheres of cool white dwarfs using both a chemical model and ab initio simulations. A chemical model is developed for the low-ionization limit that includes the species He, He+, He2+, and electrons, and interactions between them. The ab initio calculations consist in quantum molecular dynamics (QMD) simulations. We use the generalized gradient approximation (GGA) to calculate the equation of state and the electrical and optical properties within the linear response theory. We further use an exact exchange hybrid (PBE0) density functional as well as the GW approximation to estimate the uncertainties on the electrical and optical properties resulting from the GGA approximation. While both the chemical model and the QMD simulations are in excellent agreement with the measured equation of state, a qualitative discrepancy exists with the measured conductivity.

P. M. Kowalski, S. Mazevet, D. Saumon, and M. Challacombe

2007-08-10T23:59:59.000Z

116

Modelling the optical properties of composite and porous interstellar grains  

E-Print Network [OSTI]

There are indications that interstellar and interplanetary dust grains have an inhomogeneous and fluffy structure. We investigate different methods to describe light scattering by such composite particles. Both a model of layered particles and discrete dipole calculations for particles with Rayleigh and non-Rayleigh inclusions are used. The calculations demonstrate that porosity is a key parameter for determining light scattering. We find that the optical properties of the layered particles depend on the number and position of layers if the number of layers is small ($\\la 15$). For a larger number of layers the scattering characteristics become independent of the layer sequence. The optical properties of particles with inclusions depend on the size of inclusions provided the porosity is large. The scattering characteristics of very porous particles with inclusions of different sizes are found to be close to those of multi-layered spheres. We compare the results of these calculations with the predictions of the effective medium theories (EMT) which are often used in astronomy as a tool to calculate the optical properties of composite particles. The results of our analysis show that the internal structure of grains (layers versus inclusions) only slightly affects the optics of particles provided the porosity does not exceed 50%. It is also demonstrated that in this case the optical properties of composite grains calculated with EMT agree with the results of the exact method for layered particles. For larger porosity, the standard EMT rules (i.e., Garnett and Bruggeman rules) give reliable results for particles with Rayleigh inclusions only.

N. V. Voshchinnikov; V. B. Il'in; Th. Henning

2004-09-19T23:59:59.000Z

117

Physical Properties of Ambient and Laboratory-Generated Secondary Organic Aerosol  

SciTech Connect (OSTI)

The size and thickness of organic aerosol particles collected by impaction in five field campaigns were compared to those of laboratory generated secondary organic aerosols (SOA). Scanning transmission x-ray microscopy (STXM) was used to measure the total carbon absorbance (TCA) by individual particles as a function of their projection areas on the substrate. Because they flatten less upon impaction, particles with higher viscosity and surface tension can be identified by a steeper slope on a plot of TCA vs. size. The slopes of the ambient data are statistically similar indicating a small range of average viscosities and surface tensions across five field campaigns. Steeper slopes were observed for the plots corresponding to ambient particles, while smaller slopes were indicative of the laboratory generated SOA. This comparison indicates that ambient organic particles have higher viscosities and surface tensions than those typically generated in laboratory SOA studies.

O'Brien, Rachel E.; Neu, Alexander; Epstein, Scott A.; MacMillan, Amanda; Wang, Bingbing; Kelly, Stephen T.; Nizkorodov, Sergey; Laskin, Alexander; Moffet, Ryan C.; Gilles, Mary K.

2014-06-17T23:59:59.000Z

118

Optical Properties of Functional Composite Silver Nanoparticles and Their Potential Use in Reproductive Medicine  

Science Journals Connector (OSTI)

Silver nanoparticles are promising product of nanotechnology with attractive physicochemical and biological properties. The main aim of the study was to investigate optical properties...

Syrvatka, Vasyl J; Slyvchuk, Yurij I; Rozgoni, Ivan I; Gevkan, Ivan I; Bilyy , Oleksandr I

119

Lanthanides-clay nanocomposites: Synthesis, characterization and optical properties  

SciTech Connect (OSTI)

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.

Celedon, Salvador; Quiroz, Carolina [Universidad Tecnologica Metropolitana, Department of Chemistry, P.O. Box 9845, Santiago (Chile); Gonzalez, Guillermo [Universidad de Chile, Faculty of Science, Department of Chemistry, P.O. Box 653, Santiago (Chile); Sotomayor Torres, Clivia M. [University College Cork, Tyndall National Institute, Lee Maltings, Cork (Ireland); Catalan Institute of Nanotechnology, Campus de Bellaterra, Edifici CM3, ES 08193, Institute of Research and Advanced Studies ICREA, 08010 Barcelona (Spain); Benavente, Eglantina [Universidad Tecnologica Metropolitana, Department of Chemistry, P.O. Box 9845, Santiago (Chile)], E-mail: ebenaven@utem.cl

2009-05-06T23:59:59.000Z

120

Theory of the optical properties of ionic crystal cubes  

Science Journals Connector (OSTI)

A theory is developed for the optical properties of particles of arbitrary shape, composed of a homogeneous isotropic material with a dielectric constant ?(?). The particles are so small that retardation can be neglected. An expression is obtained for the average dielectric constant of a medium containing a small fractional volume of particles. Calculations for a cube show that six resonances contribute to the optical absorption. They span a frequency range such that ??(?), the real part of the dielectric constant, lies between -3.68 and -0.42, as contrasted with the single resonance for a sphere at ??(?)=-2. A comparison of the theory with experiments on the optical absorption of NaCl and MgO cubes shows that the width of the absorption peak can be explained by the frequency range of the cube resonances. Previous theories which assumed spherical particles required an unphysically high damping in ?(?) to account for the width.

R. Fuchs

1975-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Determining the Solar Optical Properties of Windows with Shading Devices-  

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

Determining the Solar Optical Properties of Windows with Shading Devices- Determining the Solar Optical Properties of Windows with Shading Devices- New Measurement and Modeling Techniques Speaker(s): Nathan Kotey Date: October 5, 2009 - 12:00pm Location: 90-3122 The global interest to reduce energy use in buildings has focussed new efforts to more aggressively reduce energy used by all major building components, such as window systems. Although good progress has been made in reducing heat loss, the contribution of windows to heat gain, peak cooling loads and cooling energy consumption is increasingly viewed globally as a problem. While glass coatings provide some control, shading devices on windows have the potential to do an even better job to reduce peak cooling load and annual energy consumption because there are more design parameters

122

aerosols | EMSL  

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

aerosols aerosols Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a candidate material for...

123

Overview of the COPS Aerosol and Cloud Microphysics (ACM) Subgroup...  

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

properties of orographically induced clouds and how do these depend on dynamics, thermodynamics, and aerosol microphysics? * What is the role of aerosols and changing cloud...

124

Techniques and Methods Used to Determine the Aerosol Best Estimate Value-Added Product at SGP Central Facility  

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

Determine the Aerosol Best Estimate Value-Added Product at SGP Central Facility C. Sivaraman, D. D. Turner, and C. J. Flynn Pacific Northwest National Laboratory Richland, Washington Objective Profiles of aerosol optical properties are needed for radiative closure exercises such as the broadband heating rate profile (BBHRP) project (Mlawer et al. 2002) and the Shortwave Quality Measurement Experiment (QME). Retrieving cloud microphysical properties using radiation measurements in the shortwave, such as the spectral retrieval technique described in Daniel et al. (2002), also require the optical properties of the aerosols so that they can be accounted for in the retrieval process. The objective of the aerosol best estimate (ABE) value-added procedure (VAP) is to provide profiles of

125

REPRESENTING AEROSOL DYNAMICS AND PROPERTIES IN ATMOSPHERIC CHEMICAL TRANSPORT MODELS BY THE METHOD OF MOMENTS  

E-Print Network [OSTI]

, troposphere · Modification of cloud physical properties - hydrology and climate · Modification of fog, cloud

Schwartz, Stephen E.

126

Nonlinear Quantum Optical Springs and Their Nonclassical Properties  

E-Print Network [OSTI]

The original idea of quantum optical spring arises from the requirement of quantization of the frequency of oscillations in the Hamiltonian of harmonic oscillator. This purpose is achieved by considering a spring whose constant (and so its frequency) depends on the quantum states of another system. Recently, it is realized that by the assumption of frequency modulation of $\\omega$ to $\\omega\\sqrt{1+\\mu a^\\dagger a}$ the mentioned idea can be established. In the present paper, we generalize the approach of quantum optical spring with particular attention to the {\\it dependence of frequency to the intensity of radiation field} that {\\it naturally} observes in the {\\it nonlinear coherent states}, from which we arrive at a physical system has been called by us as {\\it nonlinear quantum optical spring}. Then, after the introduction of the generalized Hamiltonian of nonlinear quantum optical spring and it's solution, we will investigate the nonclassical properties of the obtained states. Specially, typical collapse and revival in the distribution functions and squeezing parameters, as particular quantum features, will be revealed.

M. J. Faghihi; M. K. Tavassoly

2014-07-29T23:59:59.000Z

127

Spatial characteristics of the difference between MISR and MODIS aerosol optical depth retrievals over mainland Southeast Asia  

E-Print Network [OSTI]

autoregressive (SAR) model Spatial clustering Data assimilation Mainland Southeast Asia The difference between satellite, aerosol products generated using data from these two sensors often exhibit noticeable differences Resolution Imaging Spectroradiometer (MODIS) aboard the NASA Earth Observation System's Terra satellite

Shi, Tao

128

Electrical and optical properties of p-type InN  

E-Print Network [OSTI]

Electrical and optical properties of p-type InN Marie A.thermoelectric and electrical properties of Mg doped InNthe temperature dependent electrical properties, the sign of

Mayer, M.A.

2013-01-01T23:59:59.000Z

129

Syntheses, Structure, Magnetism, and Optical Properties of the Interlanthanide Sulfides delta-Ln2-xLuxS3 (Ln = Ce, Pr, Nd)  

E-Print Network [OSTI]

Syntheses, Structure, Magnetism, and Optical Properties ofstructure determination, magnetism, and optical propertiesSusceptibility Measurements. Magnetism data were measured on

Jin, Geng Bang

2008-01-01T23:59:59.000Z

130

BNL | Aerosol, Cloud, Precipitation Interactions  

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

Cloud-Aerosol-Precipitation Interactions Cloud-Aerosol-Precipitation Interactions Atmospheric aerosols exert important "indirect effects" on clouds and climate by serving as cloud condensation nuclei (CCN) and ice nuclei that affect cloud radiative and microphysical properties. For example, an increase in CCN increases the number concentration of droplets enhances cloud albedo, and suppresses precipitation that alters cloud coverage and lifetime. However, in the case of moist and strong convective clouds, increasing aerosols may increase precipitation and enhance storm development. Although aerosol-induced indirect effects on climate are believed to have a significant impact on global climate change, estimating their impact continues to be one of the most uncertain climate forcings.

131

Optical method for determining the mechanical properties of a material  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

132

Optical method for determining the mechanical properties of a material  

DOE Patents [OSTI]

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.

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

1998-12-01T23:59:59.000Z

133

Bio-optical properties of oceanic waters: A reappraisal Andre Morel  

E-Print Network [OSTI]

Bio-optical properties of oceanic waters: A reappraisal Andre´ Morel Laboratoire de Physique et, California Abstract. The apparent optical properties (AOPs) of oceanic case 1 waters were previously analyzed describing the trophic conditions of water bodies. From these empirical relationships a bio-optical model

California at Santa Barbara, University of

134

Posters Ship-Based Measurements of Cloud Optical Properties  

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

7 7 Posters Ship-Based Measurements of Cloud Optical Properties During the Atlantic Stratocumulus Transition Experiment A. B. White Cooperative Institute for Research in Environmental Sciences University of Colorado at Boulder National Oceanic and Atmospheric Administration Boulder, Colorado C. W. Fairall National Oceanic and Atmospheric Administration Environmental Research Laboratories Environmental Technology Laboratory Boulder, Colorado Introduction The Atlantic Stratocumulus Transition Experiment (ASTEX), conducted in June 1992, was designed with the broad goal of improving the dynamical, radiative, and microphysical models of marine boundary layer (MBL) clouds. This goal was pursued by combining measurements from a number of different platforms including aircraft,

135

Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem  

SciTech Connect (OSTI)

This study assesses the ability of the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model to simulate boundary layer structure, aerosols, stratocumulus clouds, and energy fluxes over the Southeast Pacific Ocean. Measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals (i.e., products from the MODerate resolution Imaging Spectroradiometer (MODIS), Clouds and Earth's Radiant Energy System (CERES), and GOES-10) are used for this assessment. The Morrison double-moment microphysics scheme is newly coupled with interactive aerosols in the model. The 31-day (15 October-16 November 2008) WRF-Chem simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations in the microphysics scheme and simplified cloud and aerosol treatments in the radiation scheme. The well-simulated aerosol quantities (aerosol number, mass composition and optical properties), and the inclusion of full aerosol-cloud couplings lead to significant improvements in many features of the simulated stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness. In addition to accounting for the aerosol direct and semi-direct effects, these improvements feed back to the simulation of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengthens the temperature and humidity gradients within the capping inversion layer and lowers the marine boundary layer (MBL) depth by 130 m from that of the MET simulation. These differences are associated with weaker entrainment and stronger mean subsidence at the top of the MBL in AERO. Mean top-of-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity) and aerosol quantities (e.g., underestimations of accumulation mode aerosol number) might affect simulated stratocumulus and energy fluxes over the Southeastern Pacific, and require further investigation. The well-simulated timing and outflow patterns of polluted and clean episodes demonstrate the model's ability to capture daily/synoptic scale variations of aerosol and cloud properties, and suggest that the model is suitable for studying atmospheric processes associated with pollution outflow over the ocean. The overall performance of the regional model in simulating mesoscale clouds and boundary layer properties is encouraging and suggests that reproducing gradients of aerosol and cloud droplet concentrations and coupling cloud-aerosol-radiation processes are important when simulating marine stratocumulus over the Southeast Pacific.

Yang Q.; Lee Y.; Gustafson Jr., W. I.; Fast, J. D.; Wang, H.; Easter, R. C.; Morrison, H.; Chapman, E. G.; Spak, S. N.; Mena-Carrasco, M. A.

2011-12-02T23:59:59.000Z

136

How the pitch of a holey optical fiber affects its lightguide properties  

Science Journals Connector (OSTI)

This paper discusses how scaling (increasing) the transverse dimensions of a holey optical quartz fiber affects its lightguide properties. It is established that a limiting pitch...

Dukel'skii, K V; Kondrat'ev, Yu N; Komarov, A V; Ter-Nersesyants, E V; Khokhlov, A V; Shevandin, V S

2006-01-01T23:59:59.000Z

137

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

E-Print Network [OSTI]

Syntheses, Structure, Magnetism, and Optical Properties ofin some cases atypical magnetism. 1-21 New developments insimpler systems in term of magnetism and less investigated,

Jin, Geng Bang

2007-01-01T23:59:59.000Z

138

Calculation of optical and electronic properties of modeled titanium dioxide films of different densities  

Science Journals Connector (OSTI)

The electronic and optical properties of TiO2 atomic structures representing simulated thin films have been investigated using density functional theory. Suitable model...

Turowski, Marcus; Amotchkina, Tatiana; Ehlers, Henrik; Jupé, Marco; Ristau, Detlev

2014-01-01T23:59:59.000Z

139

Multi-year Satellite and Surface Observations of AOD in support of Two-Column Aerosol Project (TCAP) Field Campaign  

SciTech Connect (OSTI)

We use combined multi-year measurements from the surface and space for assessing the spatial and temporal distribution of aerosol properties within a large (~400x400 km) region centered on Cape Cod, Massachusetts, along the East Coast of the United States. The ground-based Aerosol Robotic Network (AERONET) measurements at Martha’s Vineyard Coastal Observatory (MVCO) site and Moderate Resolution Imaging Spectrometer (MODIS) sensors on board the Terra and Aqua satellites provide horizontal and temporal variations of aerosol optical depth, while the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) offers the altitudes of aerosol-layers. The combined ground-based and satellite measurements indicated several interesting features among which were the large differences in the aerosol properties observed in July and February. We applied the climatology of aerosol properties for designing the Two-Column Aerosol Project (TCAP), which is supported by the U.S. Department of Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) Program. The TCAP field campaign involves 12-month deployment (started July 1, 2012) of the ground-based ARM Mobile Facility (AMF) and Mobile Aerosol Observing System (MAOS) on Cape Cod and complimentary aerosol observations from two research aircraft: the DOE Gulfstream-1 (G-1) and the National Aeronautics and Space Administration (NASA) B200 King Air. Using results from the coordinated G-1 and B200 flights during the recent (July, 2012) Intensive Observation Period, we demonstrated that the G-1 in situ measurements and B200 active remote sensing can provide complementary information on the temporal and spatial changes of the aerosol properties off the coast of North America.

Kassianov, Evgueni I.; Chand, Duli; Berg, Larry K.; Fast, Jerome D.; Tomlinson, Jason M.; Ferrare, R.; Hostetler, Chris A.; Hair, John

2012-11-01T23:59:59.000Z

140

E-Print Network 3.0 - apparent optical properties Sample Search...  

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

Mayaguez Collection: Geosciences 7 SIL PUBLICATIONS YEARS 2000 2004 Summary: . 1-13. Armstrong, R.A., J.M. Lpez, and F. Gilbes, "Apparent Water Optical Properties... Properties...

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Enhancement of electro-optic properties in liquid crystal devices via titanium nanoparticle doping  

Science Journals Connector (OSTI)

We investigated the properties of nematic liquid crystal device (NLC) doped with titanium (Ti) nanoparticle (~100nm). The electro-optic (EO) properties of LCs changed according to Ti...

Ha, Yong-Seok; Kim, Hyung-Jun; Park, Hong-Gyu; Seo, Dae-Shik

2012-01-01T23:59:59.000Z

142

Correlations between Optical, Chemical and Physical Properties of Biomass Burn Aerosols  

E-Print Network [OSTI]

of potassium in biomass combustion, Proceedings of thethan those from biomass combustion. In Figure 3, ? ap valuesspectral dependence for the biomass combustion particulates.

2008-01-01T23:59:59.000Z

143

Variations of aerosol optical properties during the extreme solar event in January 2005  

E-Print Network [OSTI]

to undergo nuclear reactions and produce a flux of neutrons detectable by ground-based neutron monitors. Some energy input of cosmic rays into the atmosphere is minor, they form the main source of ionization (cosmic ray induced ionization ­ CRII) of the low and middle atmosphere. Therefore, cosmic rays may, via CRII

Usoskin, Ilya G.

144

Observations of the first aerosol indirect effect in shallow cumuli  

SciTech Connect (OSTI)

Data from the Cumulus Humilis Aerosol Processing Study (CHAPS) are used to estimate the impact of both aerosol indirect effects and cloud dynamics on the microphysical and optical properties of shallow cumuli observed in the vicinity of Oklahoma City, Oklahoma. Not surprisingly, we find that the amount of light scattered by the clouds is dominated by their liquid water content (LWC), which in turn is driven by cloud dynamics. However, removing the effect of cloud dynamics by examining the scattering normalized by LWC shows a strong sensitivity of scattering to pollutant loading. These results suggest that even moderately sized cities, like Oklahoma City, can have a measureable impact on the optical properties of shallow cumuli.

Berg, Larry K.; Berkowitz, Carl M.; Barnard, James C.; Senum, Gunar; Springston, Stephen R.

2011-02-08T23:59:59.000Z

145

Analysis of nonlinear optical properties in donor–acceptor materials  

SciTech Connect (OSTI)

Time-dependent density functional theory has been used to calculate nonlinear optical (NLO) properties, including the first and second hyperpolarizabilities as well as the two-photon absorption cross-section, for the donor-acceptor molecules p-nitroaniline and dimethylamino nitrostilbene, and for respective materials attached to a gold dimer. The CAMB3LYP, B3LYP, PBE0, and PBE exchange-correlation functionals all had fair but variable performance when compared to higher-level theory and to experiment. The CAMB3LYP functional had the best performance on these compounds of the functionals tested. However, our comprehensive analysis has shown that quantitative prediction of hyperpolarizabilities is still a challenge, hampered by inadequate functionals, basis sets, and solvation models, requiring further experimental characterization. Attachment of the Au{sub 2}S group to molecules already known for their relatively large NLO properties was found to further enhance the response. While our calculations show a modest enhancement for the first hyperpolarizability, the enhancement of the second hyperpolarizability is predicted to be more than an order of magnitude.

Day, Paul N. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States) [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); General Dynamics Information Technology, Inc., Dayton, Ohio 45431 (United States); Pachter, Ruth [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States)] [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); Nguyen, Kiet A. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States) [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); UES, Inc., Dayton, Ohio 45432 (United States)

2014-05-14T23:59:59.000Z

146

Optical properties of the mouse eye Ying Geng,1,2,*  

E-Print Network [OSTI]

Optical properties of the mouse eye Ying Geng,1,2,* Lee Anne Schery,1 Robin Sharma,1,2 Alfredo, University of Rochester, Rochester, NY, 14627, USA 2 The Institute of Optics, University of Rochester indicate that the optical quality of the mouse eye assessed by measurement of its aberrations is remarkably

147

CARES: Carbonaceous Aerosol and Radiative Effects Study Operations Plan  

SciTech Connect (OSTI)

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.

Zaveri, RA; Shaw, WJ; Cziczo, DJ

2010-07-12T23:59:59.000Z

148

How do A-train Sensors Intercompare in the Retrieval of Above-Cloud Aerosol Optical Depth? A Case Study-based Assessment  

SciTech Connect (OSTI)

We inter-compare the above-cloud aerosol optical depth (ACAOD) of biomass burning plumes retrieved from different A-train sensors, i.e., MODIS, CALIOP, POLDER, and OMI. These sensors have shown independent capabilities to detect and retrieve aerosol loading above marine boundary layer clouds--a kind of situation often found over the Southeast Atlantic Ocean during dry burning season. A systematic one-to-one comparison reveals that, in general, all passive sensors and CALIOP-based research methods derive comparable ACAOD with differences mostly within 0.2 over homogeneous cloud fields. The 532-nm ACAOD retrieved by CALIOP operational algorithm is largely underestimated; however, it’s 1064-nm AOD when converted to 500 nm shows closer agreement to the passive sensors. Given the different types of sensor measurements processed with different algorithms, the close agreement between them is encouraging. Due to lack of adequate direct measurements above cloud, the validation of satellite-based ACAOD retrievals remains an open challenge. The inter-satellite comparison, however, can be useful for the relative evaluation and consistency check.

Jethva, H. T.; Torres, O.; Waquet, F.; Chand, Duli; Hu, Yong X.

2014-01-16T23:59:59.000Z

149

Parameterization of shortwave ice cloud optical properties for various particle habits  

E-Print Network [OSTI]

: Remote sensing; KEYWORDS: clouds, optical properties, radiative transfer, ice particles 1. IntroductionParameterization of shortwave ice cloud optical properties for various particle habits Jeffrey R 2001; accepted 1 December 2001; published 12 July 2002. [1] The relative importance of ice clouds

Baum, Bryan A.

150

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

SciTech Connect (OSTI)

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.

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

2012-08-22T23:59:59.000Z

151

Putting DFT to the Test: A First Principles Study of Electronic, Magnetic and Optical Properties of Co3O4  

Science Journals Connector (OSTI)

Putting DFT to the Test: A First Principles Study of Electronic, Magnetic and Optical Properties of Co3O4 ...

Vijay Singh; Monica Kosa; Koushik Majhi; Dan Thomas Major

2014-11-25T23:59:59.000Z

152

Effect of doping Fe and Si on electronic structure and optical Properties of CdS  

Science Journals Connector (OSTI)

The geometrical structure, electronic properties and optical properties of CdS and M@CdS (M=Fe, Si) were studied systemically with first principles density functional theory. The band structure and density of states have been calculated to analyze the effect of the doping Fe and Si elements on the electronic properties and magnetic properties of CdS. The results show that all the conductive, magnetic and optical properties of CdS are changed by the doped elements. Both obvious and insignificant changes are found in some cases, which provide helpful guide for preparing doped CdS materials.

Yan-Xiao Han; Chuan-Lu Yang; Jun-Sheng Yang; Mei-Shan Wang; Xiao-Guang Ma

2013-01-01T23:59:59.000Z

153

Aerosol-Cloud-Precipitation Interactions in the Trade Wind Boundary Layer.  

E-Print Network [OSTI]

??This dissertation includes an overview of aerosol, cloud, and precipitation properties associated with shallow marine cumulus clouds observed during the Barbados Aerosol Cloud Experiment (BACEX,… (more)

Jung, Eunsil

2012-01-01T23:59:59.000Z

154

ARM - Evaluation Product - Organic Aerosol Component VAP  

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

ProductsOrganic Aerosol Component VAP ProductsOrganic Aerosol Component VAP 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 2011.01.08 - 2012.03.24 Site(s) SGP General Description 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 is poorly characterized and its life cycle insufficiently represented in models. As a result, current models are unable to simulate OA concentrations and properties. This deficiency represents a large source of uncertainty in the quantification of aerosol direct and indirect effects and the prediction of future climate change. The Organic Aerosol Component (OACOMP) value-added product (VAP) uses

155

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

Office of Scientific and Technical Information (OSTI)

mounting could induce localized high stress areas, causing the optical element to fracture. Five candidate adhesives were selected and evaluated using standardized test methods...

156

Optical and Transport Properties of Organic Molecules: Methods and Applications  

E-Print Network [OSTI]

method: Electronic structure calculations without a basis.temperature electronic-structure calculations. Phys. Rev. B,Louie. Ab initio calculation of the electronic and optical

Strubbe, David Alan

2012-01-01T23:59:59.000Z

157

Engineering the optical properties of subwavelength devices and materials  

E-Print Network [OSTI]

Many applications demand materials with seemingly incompatible optical characteristics. For example, immersion photolithography is a resolution enhancing technique used to fabricate the ever-shrinking nanostructures in ...

Anant, Vikas, 1980-

2007-01-01T23:59:59.000Z

158

Detection of internally mixed Asian dust with air pollution aerosols using a polarization optical particle counter and a polarization-sensitive two-wavelength lidar  

Science Journals Connector (OSTI)

Abstract East Asia is a unique region where mineral dust (Asian dust) sources are located near urban and industrial areas. Asian dust is often mixed with air pollution aerosols during transportation. It is important to understand the mixing states of Asian dust and other aerosols, because the effects on the environment and human health differ depending on the mixing state. We studied the mixing states of Asian dust using a polarization particle counter (POPC) that measures the forward scattering and the two polarization components of backscattering for single particles and a polarization-sensitive (532 nm) two-wavelength (1064 nm and 532 nm) lidar. We conducted the simultaneous observations using the POPC and the lidar in Seoul from March to December 2013 and captured the characteristics of pure Asian dust and internally mixed polluted Asian dust. POPC measurements indicated that the density of large particles was lower in polluted Asian dust that transported slowly over the polluted areas than in pure Asian dust that transported quickly from the dust source region. Moreover, the backscattering depolarization ratio was smaller for all particle sizes in polluted dust. The optical characteristics measured using the lidar were consistent with the POPC measurements. The backscattering color ratio of polluted dust was comparable to that of pure dust, but the depolarization ratio was lower for polluted dust. In addition, coarse non-spherical particles (Asian dust) almost always existed in the background, and the depolarization ratio had seasonal variation with a lower depolarization ratio in the summer. These results suggest background Asian dust particles are internally mixed in the summer.

Nobuo Sugimoto; Tomoaki Nishizawa; Atsushi Shimizu; Ichiro Matsui; Hiroshi Kobayashi

2015-01-01T23:59:59.000Z

159

E-Print Network 3.0 - aerosol generation characterization Sample...  

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

Summary: , Brookhaven National Laboratory: "Characterization of Aerosol Organic Matter: Detection, Formation and Optical... : "Atmospheric Formation, Transformation, and...

160

3D EFFECTS ON SPECTRALLY INVARIANT BEHAVIOR NEAR CLOUD EDGES: IMPLICATIONS FOR RETRIEVING AEROSOL AND CLOUD PROPERTIES IN  

E-Print Network [OSTI]

3D EFFECTS ON SPECTRALLY INVARIANT BEHAVIOR NEAR CLOUD EDGES: IMPLICATIONS FOR RETRIEVING AEROSOL between cloudy and clear air is always ambiguous, and because effects of the 3D nature of clouds will demonstrate how 3D effects may modulate the spectrally invariant relationships. We will also show the extent

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Electrical and optical properties of polycrystalline Ag-doped CdS thin films  

Science Journals Connector (OSTI)

CdS and CdS:Ag thin films were prepared using the spray pyrolysis technique. The prepared films were deposited on glass substrate kept at a temperature of (420±10) °C. The optical and electrical properties hav...

M. A. Khalid; H. A. Jassem

1993-03-01T23:59:59.000Z

162

Optical Properties of Saharan Dust and Asian Dust: Application to Radiative Transfer Simulations  

E-Print Network [OSTI]

Because the bulk optical properties of dust are largely dependent on their chemical composition, published reports from numerous dust field studies enabled us to compile observation data sets to derive the effective complex refractive indices...

Fang, Guangyang

2012-07-16T23:59:59.000Z

163

Electronic structure and optical properties of ZnSe from first-principles calculations  

Science Journals Connector (OSTI)

We have performed the first-principles calculations in the framework of density functional theory to determine the electronic structure and optical properties of zinc-blende ZnSe.

Yu, Zhiqiang; Xu, Zhimou; Wu, Xinghui; Ma, Zhichao

164

Influence of river discharge and ocean currents on coastal optical properties  

Science Journals Connector (OSTI)

Abstract The variability in the optical properties of a coastal region influenced by river runoff and multiple ocean currents in a southern hemisphere setting has been studied. The study area, Tasmanian coastal waters, is influenced by subtropical currents such as the East Australian Current (EAC) and the Zeehan Current (ZC) mix with cooler sub-Antarctic water (SAW). Freshwater discharges from rivers around the island and their mixing with the ocean currents also influence Tasmanian coastal waters. This study was performed to understand the influence of hydrodynamic processes on coastal optical properties and underwater light propagation. Physical, biogeochemical and optical properties were measured in Tasmanian coastal water during the austral autumn of 2007. In this study we found that physical properties have a good correlation with optical properties indicating the role played by hydrodynamic processes in distribution of optically active substances, optical properties of the water mass and underwater light propagation. Analysis of in situ salinity and temperature confirmed the presence of relatively cooler ZC in the South-West region, a cooler mixture of the ZC and SAW in the South-East, warm and saline EAC waters along the East coast and relatively cooler and fresh Bass straight waters along the North coast. In Tasmanian coastal waters light absorption in the water column is controlled by Coloured Dissolved Organic Matter (CDOM) with regionally varying contributions from Non-Algal Particulate (NAP) matter and phytoplankton. Absorption due to CDOM and NAP show a conservative mixing behaviour indicating that these biogeochemical components were delivered by the river and diluted in the coastal water. Suspended particulate matter in Tasmanian coastal water are highly scattering in nature and the beam attenuation is mainly due to light scattering. Variability in probability of light backscattering was mainly due to varying availability of non-algal particulate matter in the surface waters, which is controlled by river discharges in the region. Beam attenuation was high in coastal waters that are influenced by river runoff and increasing beam attenuation had constrained the underwater light propagation in these coastal waters. In the absence of major rivers along the East coast, optical properties were mainly influenced by the EAC water mass. Optical properties of the East coast were clearly different from the rest of the Tasmanian regions. In other regions the influence of ocean currents is subtle due to strong mixing between river discharges and ocean water mass. Overall, analysis of bio-optical properties shows that optical properties are constrained by regional hydrodynamic processes. Results presented highlight importance of using hydrodynamic process specific bio-optical properties and parameterisation in modelling light propagation in coastal ecosystems that are influenced by multiple ocean currents and river discharges.

Nagur Cherukuru; Vittorio E. Brando; Thomas Schroeder; Lesley A. Clementson; Arnold G. Dekker

2014-01-01T23:59:59.000Z

165

Optical measurement of biomechanical properties of individual erythrocytes from a sickle cell patient  

E-Print Network [OSTI]

Optical measurement of biomechanical properties of individual erythrocytes from a sickle cell July 2012 Available online 20 July 2012 Keywords: Sickle cell disease Red blood cell Cell biomechanics Cell membrane Optical measurement a b s t r a c t Sickle cell disease (SCD) is characterized

Dao, Ming

166

Optical properties of Zircaloy and Zircaloy oxide by ellipsometry  

Science Journals Connector (OSTI)

The optical constants of Zircaloy 2 and 4, which are alloys of zirconium and their thermal oxides, are determined by ellipsometry over a 0.3131–3.39-?m wavelength range. Both the...

Bashara, N M; Peng, Y -K

1980-01-01T23:59:59.000Z

167

Structural, electronic, and optical properties of wurtzite and rocksalt InN under pressure  

Science Journals Connector (OSTI)

Structural stability, electronic, and optical properties of InN under high pressure are studied using the first-principles calculations. The lattice constants and electronic band structure are found consistent with the available experimental and theoretical values. The pressure of the wurtzite-to-rocksalt structural transition is 13.4 GPa, which is in an excellent agreement with the most recent experimental values. The optical characteristics reproduce the experimental data thus justifying the feasibility of our theoretical predictions of the optical properties of InN at high pressures.

Man-Yi Duan; Lin He; Ming Xu; Ming-Yao Xu; Shuyan Xu; Kostya (Ken) Ostrikov

2010-01-13T23:59:59.000Z

168

Optical properties of lanthanide-containing halide-modified zinc tellurite glasses  

SciTech Connect (OSTI)

As part of an ongoing investigation to characterize the properties and structure of Zn halide-Te oxide glasses, we report preliminary measurements of the optical properties of several Nd- and Er-doped tellurites. Measurements include fluorescence lifetimes and estimates of the theoretical radiative lifetimes (from traditional Judd-Ofelt analysis of optical absorption spectra) as well as phonon sideband studies sensitive to vibrational characteristics near the rare earth ion. Response of these optical features to the substitution of alternative halides is examined.

Sidebottom, D.L.; Hruschka, M.A. [New Mexico Univ., Albuquerque, NM (United States); Potter, B.G.; Brow, R.K.; Hudgens, J.J. [Sandia National Labs., Albuquerque, NM (United States)

1996-12-31T23:59:59.000Z

169

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

DOE Patents [OSTI]

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.

Zelepouga, Serguei A. (Hoffman Estates, IL); Rue, David M. (Chicago, IL); Saveliev, Alexei V. (Chicago, IL)

2011-03-15T23:59:59.000Z

170

Optical properties of silicon carbide for astrophysical applications I. New laboratory infrared reflectance spectra and optical constants  

E-Print Network [OSTI]

Silicon Carbide (SiC) optical constants are fundamental inputs for radiative transfer models of astrophysical dust environments. However, previously published values contain errors and do not adequately represent the bulk physical properties of the cubic (beta) SiC polytype usually found around carbon stars. We provide new, uncompromised optical constants for beta- and alpha-SiC derived from single-crystal reflectance spectra and investigate quantitatively whether there is any difference between alpha- and beta-SiC that can be seen in infrared spectra and optical functions. Previous optical constants for SiC do not reflect the true bulk properties, and they are only valid for a narrow grain size range. The new optical constants presented here will allow narrow constraints to be placed on the grain size and shape distribution that dominate in astrophysical environments. In addition, our calculated absorption coefficients are much higher than laboratory measurements, which has an impact on the use of previous data to constrain abundances of these dust grains.

K. M. Pitman; A. M. Hofmeister; A. B. Corman; A. K. Speck

2008-03-10T23:59:59.000Z

171

Electronic and optical properties of nanocrystalline WO3 thin films studied by optical spectroscopy and density functional calculations  

Science Journals Connector (OSTI)

The optical and electronic properties of nanocrystalline WO3 thin films prepared by reactive dc magnetron sputtering at different total pressures (Ptot) were studied by optical spectroscopy and density functional theory (DFT) calculations. Monoclinic films prepared at low Ptot show absorption in the near infrared due to polarons, which is attributed to a strained film structure. Analysis of the optical data yields band-gap energies Eg ? 3.1 eV, which increase with increasing Ptot by 0.1 eV, and correlate with the structural modifications of the films. The electronic structures of triclinic ?-WO3, and monoclinic ?- and ?-WO3 were calculated using the Green function with screened Coulomb interaction (GW approach), and the local density approximation. The ?-WO3 and ?-WO3 phases are found to have very similar electronic properties, with weak dispersion of the valence and conduction bands, consistent with a direct band-gap. Analysis of the joint density of states shows that the optical absorption around the band edge is composed of contributions from forbidden transitions (>3 eV) and allowed transitions (>3.8 eV). The calculations show that Eg in ?-WO3 is higher than in the ?-WO3 and ?-WO3 phases, which provides an explanation for the Ptot dependence of the optical data.

Malin B Johansson; Gustavo Baldissera; Iryna Valyukh; Clas Persson; Hans Arwin; Gunnar A Niklasson; Lars Österlund

2013-01-01T23:59:59.000Z

172

Modification of the optical properties of ZnO thin films by proton implantation  

SciTech Connect (OSTI)

Highlights: ? Optical properties of proton-implanted ZnO thin film prepared by rf magneton sputtering were studied. ? Increase in the ordinary refractive index after proton implantation was explained by the polarizability. ? A slight decrease in the optical bandgap by proton implantation was identified. -- Abstract: Optical properties of proton-implanted ZnO thin film prepared by radio-frequency (rf) magneton sputtering have been studied, the optical constants being obtained from the reflectance measurements by employing Cauchy–Urbach model. Increase in the ordinary refractive index after proton implantation was explained by that in the polarizability. Besides, a slight increase in the optical band gap by proton implantation was identified and discussed in terms of the hydrogen shallow donors introduced by the proton implantation.

Ham, Yong Ju; Park, Jun Kue; Lee, W. [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of)] [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of); Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of); Park, W. [Graduate School of Management of Technology, Korea University, Seoul 136-713 (Korea, Republic of)] [Graduate School of Management of Technology, Korea University, Seoul 136-713 (Korea, Republic of)

2012-09-15T23:59:59.000Z

173

Evaluation of the carbon content of aerosols from the burn- ing of biomass in the Brazilian Amazon using thermal, op- tical and thermal-optical analysis methods  

E-Print Network [OSTI]

from Smoldering Biomass Combustion. Atmos. Chem. Phys. , 10,aerosols emitted during biomass combustion [Robinson et al.burning samples. Combustion of biomass produces EC a and

Soto-Garcia, Lydia L.

2012-01-01T23:59:59.000Z

174

Optical, electrical, and solar energy-conversion properties of gallium arsenide nanowire-array  

E-Print Network [OSTI]

Optical, electrical, and solar energy-conversion properties of gallium arsenide nanowire, and will aid in the design and optimization of nanowire-based systems for solar energy-conversion applications, and the photoelectrochemical energy-conversion properties of GaAs nanowire arrays were evaluated in contact with one

Zhou, Chongwu

175

Assessing regional scale predictions of aerosols, marine stratocumulus, and their interactions during VOCALS-REx using WRF-Chem  

SciTech Connect (OSTI)

In the recent chemistry version (v3.3) of the Weather Research and Forecasting (WRF-Chem) model, we have coupled the Morrison double-moment microphysics scheme with interactive aerosols so that full two-way aerosol-cloud interactions are included in simulations. We have used this new WRF-Chem functionality in a study focused on assessing predictions of aerosols, marine stratocumulus clouds, and their interactions over the Southeast Pacific using measurements from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) and satellite retrievals. This study also serves as a detailed analysis of our WRF-Chem simulations contributed to the VOCALS model Assessment (VOCA) project. The WRF-Chem 31-day (October 15-November 16, 2008) simulation with aerosol-cloud interactions (AERO hereafter) is also compared to a simulation (MET hereafter) with fixed cloud droplet number concentrations assumed by the default in Morrison microphysics scheme with no interactive aerosols. The well-predicted aerosol properties such as number, mass composition, and optical depth lead to significant improvements in many features of the predicted stratocumulus clouds: cloud optical properties and microphysical properties such as cloud top effective radius, cloud water path, and cloud optical thickness, and cloud macrostructure such as cloud depth and cloud base height. These improvements in addition to the aerosol direct and semi-direct effects, in turn, feed back to the prediction of boundary-layer characteristics and energy budgets. Particularly, inclusion of interactive aerosols in AERO strengths temperature and humidity gradients within capping inversion layer and lowers the MBL depth by 150 m from that of the MET simulation. Mean top-of-the-atmosphere outgoing shortwave fluxes, surface latent heat, and surface downwelling longwave fluxes are in better agreement with observations in AERO, compared to the MET simulation. Nevertheless, biases in some of the simulated meteorological quantities (e.g., MBL temperature and humidity over the remote ocean) and aerosol quantities (e.g., overestimations of supermicron sea salt mass) might affect simulated stratocumulus and energy fluxes over the SEP, and require further investigations. Although not perfect, the overall performance of the regional model in simulating mesoscale aerosol-cloud interactions is encouraging and suggests that the inclusion of spatially varying aerosol characteristics is important when simulating marine stratocumulus over the southeastern Pacific.

Yang, Qing; Gustafson, William I.; Fast, Jerome D.; Wang, Hailong; Easter, Richard C.; Morrison, H.; Lee, Y.- N.; Chapman, Elaine G.; Spak, S. N.; Mena-Carrasco, M. A.

2011-12-02T23:59:59.000Z

176

Optical properties of Mo6S3I6 nanowires  

Science Journals Connector (OSTI)

Optical reflectivity and absorbance measurements of oriented Mo6S3I6 nanowire thin films and dispersions in different solvents are presented extending from the far infrared to the ultraviolet. In spite of the highly one-dimensional character of the nanowire material and narrow electronic valence and conduction subbands, as predicted by the density-functional theory calculations, sharp Van Hove features in the optical absorption spectra are not observed, partly because of the large density of interpenetrating electron subbands and partly due to damping and disorder. The optically measured electrical conductivity extrapolated to zero frequency ?1(??0) and the calculated conductivity are significantly higher than the typical dc value from resistance measurements, indicating that disorder limits electron transport, a feature characteristic of strongly one-dimensional systems.

D. Vengust; F. Pfuner; L. Degiorgi; I. Vilfan; V. Nicolosi; J. N. Coleman; D. Mihailovic

2007-08-08T23:59:59.000Z

177

Syntheses, Structure, Magnetism, and Optical Properties of the Partial Ordered Quaternary Interlanthanide Sulfides PrLnYb2S6 (Ln = Tb, Dy)  

E-Print Network [OSTI]

Syntheses, Structure, Magnetism, and Optical Properties ofSusceptibility Measurements. Magnetism data were measured on

Jin, Geng Bang

2008-01-01T23:59:59.000Z

178

Comment on: Optical properties of expanded fluid mercury  

Science Journals Connector (OSTI)

An alternative interpretation is given for the observed reflectances. A four-parameter fit is made to the data directly from a simple model of the joint density of states. The derived energy gap is then compared to other optical and transport measurements.

Christine E. Krohn and J. C. Thompson

1980-03-15T23:59:59.000Z

179

Radiation characteristics and optical properties of filamentous cyanobacterium Anabaena cylindrica  

E-Print Network [OSTI]

in photobioreactors for wastewater treatment and ammonia or biofuel production. © 2014 Optical Society of America OCIS- ities has resulted in an accumulation of greenhouse gases in the atmosphere leading to global climate change and rising sea levels [1]. Petroleum has been used to produce (i) gasoline for transportation, (ii

Pilon, Laurent

180

Final Report for LDRD Project ''A New Era of Research in Aerosol/Cloud/Climate Interactions at LLNL''  

SciTech Connect (OSTI)

Observations of global temperature records seem to show less warming than predictions of global warming brought on by increasing concentrations of CO{sub 2} and other greenhouse gases. One of the reasonable explanations for this apparent inconsistency is that the increasing concentrations of anthropogenic aerosols may be partially counteracting the effects of greenhouse gases. Aerosols can scatter or absorb the solar radiation, directly change the planetary albedo. Aerosols, unlike CO{sub 2}, may also have a significant indirect effect by serving as cloud condensation nuclei (CCN). Increases in CCN can result in clouds with more but smaller droplets, enhancing the reflection of solar radiation. Aerosol direct and indirect effects are a strong function of the distributions of all aerosol types and the size distribution of the aerosol in question. However, the large spatial and temporal variabilities in the concentration, chemical characteristics, and size distribution of aerosols have made it difficult to assess the magnitude of aerosol effects on atmospheric radiation. These variabilities in aerosol characteristics as well as their effects on clouds are the leading sources of uncertainty in predicting future climate variation. Inventory studies have shown that the present-day anthropogenic emissions contribute more than half of fine particle mass primarily due to sulfate and carbonaceous aerosols derived from fossil fuel combustion and biomass burning. Parts of our earlier studies have been focused on developing an understanding of global sulfate and carbonaceous aerosol abundances and investigating their climate effects [Chuang et al., 1997; Penner et al., 1998]. We have also modeled aerosol optical properties to account for changes in the refractive indices with relative humidity and dry aerosol composition [Grant et al., 1999]. Moreover, we have developed parameterizations of cloud response to aerosol abundance for use in global models to evaluate the importance of aerosol/cloud interactions on climate forcing [Chuang and Penner, 1995]. Our research has been recognized as one of a few studies attempting to quantify the effects of anthropogenic aerosols on climate in the IPCC Third Assessment Report [IPCC, 2001]. Our previous assessments of aerosol climate effects were based on a general circulation model (NCAR CCM1) fully coupled to a global tropospheric chemistry model (GRANTOUR). Both models, however, were developed more than a decade ago. The lack of advanced physics representation and techniques in our current models limits us from further exploring the interrelationship between aerosol, cloud, and climate variation. Our objective is to move to a new era of aerosol/cloud/climate modeling at LLNL by coupling the most advanced chemistry and climate models and by incorporating an aerosol microphysics module. This modeling capability will enable us to identify and analyze the responsible processes in aerosol/cloud/climate interactions and therefore, to improve the level of scientific understanding for aerosol climate effects. This state-of-the-art coupled models will also be used to address the relative importance of anthropogenic and natural emissions in the spatial pattern of aerosol climate forcing in order to assess the potential of human induced climate change.

Chuang, C; Bergman, D J; Dignon, J E; Connell, P S

2002-01-31T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

ARM - PI Product - Direct Aerosol Forcing Uncertainty  

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

ProductsDirect Aerosol Forcing Uncertainty ProductsDirect Aerosol Forcing Uncertainty 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 Site(s) NSA SGP TWP General Description 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

182

Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon  

E-Print Network [OSTI]

Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies A. Nizkorodov*, Department of Chemistry, University of California, Irvine, California 92697, United

Nizkorodov, Sergey

183

Observer-dependent optical properties of stationary axisymmetric spacetimes  

E-Print Network [OSTI]

The world lines of null particles admit arbitrary parametrizations. In the presence of a family of observers one may introduce along a null world line an extension of the so-called Cattaneo's relative standard time parameter (valid for massive particles) which plays a special role. Another possibility is to use the coordinate time itself as a parameter. The relation between relative standard time and coordinate time allows for the introduction of an observer-dependent optical path and associated refraction index. Both these quantities are studied here working out explicit examples concerning familiar null orbits and observers in black hole spacetimes.

Donato Bini; Fernando de Felice; Andrea Geralico

2014-08-23T23:59:59.000Z

184

Third order nonlinear optical properties of bismuth zinc borate glasses  

SciTech Connect (OSTI)

Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi{sub 2}O{sub 3}-30ZnO-(70-x) B{sub 2}O{sub 3} (where x?=?30, 35, 40, and 45?mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due to dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (?) and the absorption cross section due to free carriers (?{sub e}) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.

Shanmugavelu, B.; Ravi Kanth Kumar, V. V., E-mail: ravi.phy@pondiuni.edu.in [Department of Physics, Pondicherry University, Puducherry 605 014 (India); Kuladeep, R.; Narayana Rao, D. [School of Physics, University of Hyderabad, Hyderabad 500046, Andhra Pradesh (India)

2013-12-28T23:59:59.000Z

185

Ultra-High Temperature Sensors Based on Optical Property  

SciTech Connect (OSTI)

In this program, Nuonics, Inc. has studied the fundamentals of a new Silicon Carbide (SiC) materials-based optical sensor technology suited for extreme environments of coal-fired engines in power production. The program explored how SiC could be used for sensing temperature, pressure, and potential gas species in a gas turbine environment. The program successfully demonstrated the optical designs, signal processing and experimental data for enabling both temperature and pressure sensing using SiC materials. The program via its sub-contractors also explored gas species sensing using SiC, in this case, no clear commercially deployable method was proven. Extensive temperature and pressure measurement data using the proposed SiC sensors was acquired to 1000 deg-C and 40 atms, respectively. Importantly, a first time packaged all-SiC probe design was successfully operated in a Siemens industrial turbine rig facility with the probe surviving the harsh chemical, pressure, and temperature environment during 28 days of test operations. The probe also survived a 1600 deg-C thermal shock test using an industrial flame.

Nabeel Riza

2008-09-30T23:59:59.000Z

186

ENGINEERED PROPERTIES IN CERAMIZED OPTICAL FIBRES W. Blanc1,*  

E-Print Network [OSTI]

... The original route proposed by LPMC to obtain DNP-doped fibres is based on the industrial MCVD process with « augmented » intrinsic properties, though using silica as host glass. Transparent glass ceramics (TGC) are then considered as they can combine the sturdiness and low cost of silica and particular spectroscopic behaviour

Paris-Sud XI, Université de

187

A review of recent measurements of optical and thermal properties of. alpha. -mercuric iodide  

SciTech Connect (OSTI)

The knowledge of the physical properties of a crystal and their relation to the nature and content of defects are essential for both applications and fundamental reasons. Alpha-mercuric iodide ({alpha}-HgI{sub 2}) is a material which was found important applications as room temperature X-ray and gamma ray detectors. Some recent thermal and optical measurements of this material, using the samples of improved crystallinity which are now available, are reviewed below. Heretofore, these properties have received less attention than the mechanical and electrical properties, particularly at elevated temperatures. In the technology of {alpha}-HgI{sub 2} where there is a continuing motivation to obtain larger single crystals without compromising the material quality, a better knowledge of the thermal and optical properties may lead to improvements in the processes of material purification, crystal growth and device fabrication.

Burger, A.; Morgan, S.H.; Silberman, E. (Fisk Univ., Nashville, TN (United States). Dept. of Physics); Nason, D.; Cheng, A.Y. (EG and G Energy Measurements, Inc., Goleta, CA (United States). Santa Barbara Operations)

1991-01-01T23:59:59.000Z

188

ZnS-Graphene nanocomposite: Synthesis, characterization and optical properties  

SciTech Connect (OSTI)

A ZnS-Graphene nanocomposite was prepared by a facile one-step hydrothermal method using zinc nitrate hexahydrate, ethylenediamine and carbon disulfide as precursors, graphene oxide as a template. The composite was characterized by X-ray power diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, Fourier transform infrared, Raman spectra and fluorescence spectroscopy. The results show that graphene oxide was reduced to graphene in the hydrothermal reaction process. Simultaneously, the graphene sheets in the composite are exfoliated and decorated with ZnS nanoparticles. Furthermore, Raman and fluorescence properties of the composite were observed. ZnS-Graphene nanocomposite displays surface-enhanced Raman scattering activity for graphene oxide, and fluorescence enhancement property compared with pure ZnS sample. - Graphical abstract: Approach of reaction makes the reduction of grapheme oxide and the deposition of Zns on the grapheme sheets occur simultaneously and overcomes the aggregation of the grapheme sheets and Zns. Highlights: Black-Right-Pointing-Pointer Graphene oxide is reduced to graphene in the hydrothermal reaction process. Black-Right-Pointing-Pointer ZnS nanoparticles are attached onto the almost transparent graphene sheets. Black-Right-Pointing-Pointer ZnS-Graphene system shows surface-enhanced Raman scattering (SERS) activity. Black-Right-Pointing-Pointer ZnS-Graphene system displays relatively better fluorescence property than pure ZnS.

Pan Shugang [Key Laboratory for Soft Chemistry and Functional Materials, Nanjing University of Science and Technology, Ministry of Education, Nanjing 210094 (China); Liu Xiaoheng, E-mail: xhliu@mail.njust.edu.cn [Key Laboratory for Soft Chemistry and Functional Materials, Nanjing University of Science and Technology, Ministry of Education, Nanjing 210094 (China)

2012-07-15T23:59:59.000Z

189

Separating Cloud Forming Nuclei from Interstitial Aerosol  

SciTech Connect (OSTI)

It has become important to characterize the physicochemical properties of aerosol that have initiated the warm and ice clouds. The data is urgently needed to better represent the aerosol-cloud interaction mechanisms in the climate models. The laboratory and in-situ techniques to separate precisely the aerosol particles that act as cloud condensation nuclei (CCN) and ice nuclei (IN), termed as cloud nuclei (CN) henceforth, have become imperative in studying aerosol effects on clouds and the environment. This review summarizes these techniques, design considerations, associated artifacts and challenges, and briefly discusses the need for improved designs to expand the CN measurement database.

Kulkarni, Gourihar R.

2012-09-12T23:59:59.000Z

190

Synthesis, structure, magnetism, and optical properties of the ordered mixed-lanthanide sulfides gamma-LnLn'S3 (Ln=La, Ce; Ln'=Er, Tm, Yb)  

E-Print Network [OSTI]

Syntheses, Structure, Magnetism, and Optical Properties ofcan be changed as Magnetism, and Optical a function of theSusceptibility Measurements. Magnetism data were measured on

2008-01-01T23:59:59.000Z

191

Magnetic-plasmonic nanoparticles for the life sciences: calculated optical properties of hybrid structures  

Science Journals Connector (OSTI)

Magnetic-plasmonic nanoparticles, combining magnetic and plasmonic components, are promising structures for use in life sciences. Optical properties of core-shell magnetite-gold nanostructures, such as the wavelength of the plasmon resonance, the extinction cross-section, and the ratio of scattering to absorption at the plasmon wavelength are critical parameters in the search for the most suitable particles for envisioned applications. Using Mie theory and the discrete dipole approximation (DDA), optical spectra as a function of composition, size, and shape of core-shell nanospheres and nanorods were calculated. Calculations were done using simulated aqueous media, used throughout the life sciences. Our results indicate that in the advantageous near-infrared region (NIR), although magnetic-plasmonic nanospheres produced by available chemical methods lack the desirable tunability of optical characteristics, magnetic-plasmonic nanorods can achieve the desired optical properties at chemically attainable dimensions. The presented results can aid in the selection of suitable magnetic-plasmonic structures for applications in life sciences. From the Clinical Editor In this basic science study, magnetic-plasmonic nanoparticles are studied for future applications in life sciences. Optical properties of core-shell magnetite-gold nanostructures, such as the wavelength of the plasmon resonance, the extinction cross-section, and the ratio of scattering to absorption at the plasmon wavelength are critical parameters in the search for the most suitable particles for proposed future applications.

Ward Brullot; Ventsislav K. Valev; Thierry Verbiest

2012-01-01T23:59:59.000Z

192

Structural, Morphological and Optical properties of Sputtered Nickel oxide Thin Films  

SciTech Connect (OSTI)

Nickel oxide (NiO) thin films have been deposited by dc reactive magnetron sputtering technique on glass substrates at various substrate temperatures in the range of 303 to 723 K. The influence of substrate temperature on structural, morphological, compositional and optical properties was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) and spectrophotometer studies. The structural properties of the films were strongly influenced by the substrate temperature. From the microstructural studies, fine and uniform grains were grown with RMS roughness of 9.4 nm at substrate temperature of 523 K. The optical results indicated that the optical transmittance of the films increases with increasing substrate temperature up to 523 K, thereafter decreases. The optical band of the films increases with substrate temperature initially, thereafter decreased at higher temperatures. The Highest optical transmittance of 60 % and optical band gap of 3.82 eV was observed in the present study.

Reddy, A. Mallikarjuna; Reddy, A. Sivasankar; Reddy, P. Sreedhara [Department of Physics, Sri Venkateswara University, Tirupati-517 502 (India)

2011-10-20T23:59:59.000Z

193

Optical Properties and Radiation-Enhanced Evaporation of Nanofluid Fuels Containing Carbon-Based Nanostructures  

E-Print Network [OSTI]

and thermal systems as an advanced heat-transfer fluid, e.g., advanced cooling of electronics systemsOptical Properties and Radiation-Enhanced Evaporation of Nanofluid Fuels Containing Carbon characteristics of nanofluid fuels with stable suspension of carbon-based nanostructures under radiation

Qiao, Li

194

How do rewritable DVDs work? Optical properties of phase-change materials  

E-Print Network [OSTI]

How do rewritable DVDs work? Optical properties of phase-change materials W. Welnic,1,2 Silvana;Outline 1 Introduction to Phase Change Materials (PCMs) 2 Open questions for Phase Change Materials;Introduction to Phase Change Materials (PCMs) Outline 1 Introduction to Phase Change Materials (PCMs) 2 Open

Botti, Silvana

195

Optical Properties of Plasmas Based on an Average-Atom Walter Johnson, Notre Dame University  

E-Print Network [OSTI]

Optical Properties of Plasmas Based on an Average-Atom Model Walter Johnson, Notre Dame University of Plasmas Based on an Average-Atom Model Walter Johnson, Notre Dame University Claude Guet, CEA/DAM Ile de of Plasmas Based on an Average-Atom Model Walter Johnson, Notre Dame University Claude Guet, CEA/DAM Ile de

Johnson, Walter R.

196

Evolution of optical properties of tin film from solid to liquid studied by spectroscopic ellipsometry and ab initio calculation  

SciTech Connect (OSTI)

The temperature dependent optical properties of tin film from solid to liquid were studied by spectroscopic ellipsometry and ab initio molecular dynamics simulations. The dielectric function of liquid Sn was different from solid, and an interband transition near 1.5?eV was easily observed in solid while it apparently disappeared upon melting. From the evolution of optical properties with temperature, an optical measurement to acquire the melting point by ellipsometry was presented. From first principles calculation, we show that the local structure difference in solid and liquid is responsible for this difference in the optical properties observed in experiment.

Zhang, D. X.; Shen, B.; Zheng, Y. X.; Wang, S. Y.; Zhang, J. B.; Yang, S. D.; Zhang, R. J.; Chen, L. Y.; Wang, C. Z.; Ho, K. M.

2014-03-24T23:59:59.000Z

197

TOWARDS CIGS SOLAR CELLS WITH REDUCED FILM THICKNESS: A STUDY OF OPTICAL PROPERTIES AND OF PHOTONIC STRUCTURES FOR LIGHT TRAPPING  

E-Print Network [OSTI]

TOWARDS CIGS SOLAR CELLS WITH REDUCED FILM THICKNESS: A STUDY OF OPTICAL PROPERTIES AND OF PHOTONIC ABSTRACT: In view of large-scale exploitation of CuIn1-xGaxSe2 (CIGS) solar cells for photovoltaic energy. In this work we perform a full study of optical properties of CIGS solar cells grown by a hybrid sputtering

198

ARM - Field Campaign - Pajarito Aerosol Coupling to Ecosystems...  

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

properties during the winter-spring transition. Opportunity to investigate fire and automobile emission interactions with biogenic aerosols will also harnessed MAOS will be...

199

Axiomatic Geometrical Optics, Abraham-Minkowski Controversy, and Photon Properties Derived Classically  

SciTech Connect (OSTI)

By restating geometrical optics within the eld-theoretical approach, the classical concept of a photon in arbitrary dispersive medium is introduced, and photon properties are calculated unambiguously. In particular, the canonical and kinetic momenta carried by a photon, as well as the two corresponding energy-momentum tensors of a wave, are derived straightforwardly from rst principles of Lagrangian mechanics. The Abraham-Minkowski controversy pertaining to the de nitions of these quantities is thereby resolved for linear waves of arbitrary nature, and corrections to the traditional formulas for the photon kinetic quantities are found. An application of axiomatic geometrical optics to electromagnetic waves is also presented as an example.

L.Y. Dodin and N.J. Fisch

2012-06-18T23:59:59.000Z

200

Green function approach for the ab initio calculation of the optical and magneto-optical properties of solids:??Accounting for dynamical many-body effects  

Science Journals Connector (OSTI)

An approach for the calculation of the optical and magneto-optical properties of solids based on the one-particle Green function is introduced in the framework of the linear muffin-tin orbital method. The approach keeps all advantages of the more accurate Korringa-Kohn-Rostoker scheme as the possibility to account for many-body effects in terms of the nonlocal energy dependent self-energy but is numerically much more efficient. Application of various proposed model self-energies for the calculation of the optical properties of bulk Ni and Fe demonstrates the great potential of the new scheme.

A. Perlov, S. Chadov, and H. Ebert

2003-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Atmospheric Radiation Measurement (ARM) Data from Cape Cod, Massachusetts for the Two-Column Aerosol Project (TCAP)  

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

The Two-Column Aerosol Project (TCAP) was designed to 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 ARM Mobile Facility and the Mobile Aerosol Observing System were deployed 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 were supplemented by two aircraft intensive observation periods, one in the summer and a second in the winter.

202

Assessment of Aerosol Radiative Impact over Oceanic Regions Adjacent to Indian Subcontinent using Multi-Satellite Analysis  

SciTech Connect (OSTI)

Using data from Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments, we have retrieved regional distribution of aerosol column single scattering albedo (parameter indicative of the relative dominance of aerosol absorption and scattering effects), a most important, but least understood aerosol property in assessing its climate impact. Consequently we provide improved assessment of short wave aerosol radiative forcing (ARF) (on both regional and seasonal scales) estimates over this region. Large gradients in north-south ARF were observed as a consequence of gradients in single scattering albedo as well as aerosol optical depth. The highest ARF (-37 W m-2 at the surface) was observed over the northern Arabian Sea during June to August period (JJA). In general, ARF was higher over northern Bay of Bengal (NBoB) during winter and pre-monsoon period, whereas the ARF was higher over northern Arabian Sea (NAS) during the monsoon and post- monsoon period. The largest forcing observed over NAS during JJA is the consequence of large amounts of desert dust transported from the west Asian dust sources. High as well as seasonally invariant aerosol single scattering albedos (~0.98) were observed over the southern Indian Ocean region far from continents. The ARF estimates based on direct measurements made at a remote island location, Minicoy (8.3°N, 73°E) in the southern Arabian Sea are in good agreement with the estimates made following multisatellite analysis.

Satheesh, S. K.; Vinoj, V.; Krishnamoorthy, K.

2010-10-01T23:59:59.000Z

203

Solar Energy Materials & Solar Cells 91 (2007) 17261732 Optical and structural properties of Ta2O5CeO2 thin films  

E-Print Network [OSTI]

Solar Energy Materials & Solar Cells 91 (2007) 1726­1732 Optical and structural properties of Ta2O5

Thirumalai, Devarajan

204

Fully relativistic description of the magneto-optical properties of arbitrary layered systems  

Science Journals Connector (OSTI)

A fully relativistic formalism is presented that allows us to define the frequency-dependent optical conductivity tensor for arbitrary layered systems in a layer-resolved way. This opens in particular the way to deal with the magneto-optical properties of magnetic surface layer systems and to calculate the corresponding magneto-optical Kerr spectra. The formalism, based on a fully relativistic description of response theory in arbitrary order, is described in some detail. For an implementation the very flexible spin polarized relativistic Korringa-Kohn-Rostoker method of band structure calculation has been used. Results of corresponding applications to the elemental ferromagnets bcc-Fe and fcc-Co treated as homogeneous layer systems are presented.

T. Huhne and H. Ebert

1999-11-01T23:59:59.000Z

205

Influence of geometry and topology of quantum graphs on their nonlinear optical properties  

Science Journals Connector (OSTI)

We analyze the nonlinear optics of quasi-one-dimensional quantum graphs and manipulate their topology and geometry to generate nonlinearities in a simple system approaching the fundamental limits of the first and second hyperpolarizabilities. We explore a huge configuration space in order to determine whether the fundamental limits may be approached for specific topologies, independent of molecular details, when the geometry is manipulated to maximize the intrinsic response. Changes in geometry result in smooth variations of the nonlinearities. Topological changes between geometrically similar systems cause profound changes in the nonlinear susceptibilities that include a discontinuity due to abrupt changes in the boundary conditions. We demonstrate the same universal scaling behavior for quantum graphs that is predicted for general quantum nonlinear optical systems near their fundamental limits, indicating that our results for quantum graphs may reflect general structure-property relationships for globally optimized nonlinear optical systems.

Rick Lytel; Shoresh Shafei; Julian H. Smith; Mark G. Kuzyk

2013-04-17T23:59:59.000Z

206

Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx  

SciTech Connect (OSTI)

We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics and cloud microphysics. We compare local time series and campaign averaged longitudinal gradients, and highlight differences in model simulations with (W) and without wet (NW) deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD) and liquid water path (LWP). Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, including the reliability required for policy analysis and geo-engineering applications.

Saide, Pablo; Spak, S. N.; Carmichael, Gregory; Mena-Carrasco, M. A.; Yang, Qing; Howell, S. G.; Leon, Dolislager; Snider, Jefferson R.; Bandy, Alan R.; Collett, Jeffrey L.; Benedict, K. B.; de Szoeke, S.; Hawkins, Lisa; Allen, Grant; Crawford, I.; Crosier, J.; Springston, S. R.

2012-03-30T23:59:59.000Z

207

Temperature dependent structural, optical and hydrophobic properties of sputtered deposited HfO{sub 2} films  

SciTech Connect (OSTI)

Hafnium oxide being high-k dielectric has been successfully utilized in electronic and optical applications. Being thermodynamically stable and having good mechanical strength, it can be used as a protective coating for outdoor HV insulators which are suffering from surface flashover problem due to contamination. In this paper, we are investigating the effect of substrate temperature on structural, optical and hydrophobic properties of hafnium oxide coating deposited over glass insulators by DC magnetron sputtering. X-ray diffraction is applied to determine the crystalline phase and crystallite size of the film. The morphology of the samples is examined using atomic force microscopy. The optical properties are studied using UV-vis-NIR spectrophotometer. The wettability of the film is investigated using contact angle meter. The thickness is measured using surface profilometer and verified through optical data. The relationship between substrate temperature with grain size, roughness, refractive index, and hydrophobicity is manifested. The maximum contact angle for HfO{sub 2} film was found to be 106° at 400°C.

Dave, V. [Department of Electrical Engineering, IIT Roorkee (India); Institute Instrumentation Centre, IIT Roorkee (India); Dubey, P.; Chandra, R. [Institute Instrumentation Centre, IIT Roorkee (India); Gupta, H. O. [Department of Electrical Engineering, IIT Roorkee (India)

2014-01-28T23:59:59.000Z

208

Structural and optical properties of zinc oxide film using RF-sputtering technique  

SciTech Connect (OSTI)

This paper reports the fabrication of zinc oxide (ZnO) film using RF-sputtering technique. Determination of the structural properties using High Resolution X-ray Diffraction (HRXRD) confirmed that ZnO film deposited on silicon (Si) substrate has a high quality. This result is in line with the Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) which were used to image the morphology of the film, in which a rough surface was demonstrated. Photoluminescence (PL) emission is included to study the optical properties of ZnO film that shows two PL peak in the UV region at 371 nm and in visible region at 530 nm respectively.

Hashim, A. J.; Jaafar, M. S.; Ghazai, Alaa J. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Pinang (Malaysia); Physics Department, Science College, Thi-Qar University (Iraq)

2012-11-27T23:59:59.000Z

209

Extensional rheology of polymers and optical properties of blown polymer films  

E-Print Network [OSTI]

Extensional Rheo logy of Polymers and Optical Properties of Blown Polymer Films. (August 1998) Jason E. Maxey, B. S. , Texas A&M University Chair of Advisory Committee: Dr. Lynden Archer Biaxial extensional flows are a commonly encountered and yet poorly.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Molecular Orientation by Bireiringence . Crystallinity by Raman Spectroscopy. Results and Discussion Film Bireiringence Raman Analysis of Crystallinity . . . . . . . 5 . . . . . 7 . . . . . 7 11 . 13 . . . 13 . . . 18 LUBRICATED SQUEEZING...

Maxey, Jason E

2012-06-07T23:59:59.000Z

210

(In,Mn)As quantum dots: Molecular-beam epitaxy and optical properties  

SciTech Connect (OSTI)

Self-assembled (In,Mn)As quantum dots are synthesized by molecular-beam epitaxy on GaAs (001) substrates. The experimental results obtained by transmission electron microscopy show that doping of the central part of the quantum dots with Mn does not bring about the formation of structural defects. The optical properties of the samples, including those in external magnetic fields, are studied.

Bouravleuv, A. D., E-mail: bour@mail.ioffe.ru; Nevedomskii, V. N. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Ubyivovk, E. V. [St. Petersburg State University (Russian Federation)] [St. Petersburg State University (Russian Federation); Sapega, V. F. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Khrebtov, A. I. [St. Petersburg Academic University, Nanotechnology Research and Education Centre (Russian Federation)] [St. Petersburg Academic University, Nanotechnology Research and Education Centre (Russian Federation); Samsonenko, Yu. B.; Cirlin, G. E.; Ustinov, V. M. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2013-08-15T23:59:59.000Z

211

Study of the Electronic and Optical Properties of Hybrid Triangular (BN)xCy Foams  

Science Journals Connector (OSTI)

Study of the Electronic and Optical Properties of Hybrid Triangular (BN)xCy Foams ... Recently, several novel three-dimensional (3D) network models constituted by all sp2-hybridized bonds(1-3) or sp2–sp3 hybridized bonds(3-7) are explored by first-principles calculations. ... We thank the computational resources and assistance provided by the Swedish National Infrastructure for Computing (SNIC) and the State Key Laboratory of Physical Chemistry of Solid Surfaces (Xiamen University). ...

Xinrui Cao; Yi Luo

2014-09-02T23:59:59.000Z

212

Modeling of the optical properties of nonspherical particles in the atmosphere  

E-Print Network [OSTI]

, Richard Orville August 2007 Major Subject: Atmospheric Sciences iii ABSTRACT Modeling of the Optical Properties of Nonspherical Particles in the Atmosphere. (August 2007) Guang Chen, B.S., Jilin University; M.S., University of Southern... [49]. However, the PSTD method applies a centered grid scheme that specifies all field components at the centers of the grid cells, as shown in Fig. A.2b. Because of this advantage, the PSTD algorithm is significantly simplified, particularly...

Chen, Guang

2009-05-15T23:59:59.000Z

213

Defects in Divided Zinc?Copper Aluminate Spinels:? Structural Features and Optical Absorption Properties  

Science Journals Connector (OSTI)

Defects in Divided Zinc?Copper Aluminate Spinels:? Structural Features and Optical Absorption Properties† ... XRD-powder data refinements (Rietveld method) have demonstrated that both compound series crystallize in the spinel structure (Fd3?m) and exhibit similar inversion rates. ... 8 This is the case of CuAlO2 composition adopting the delafossite-type structure9and which can be considered as a p-type transparent conductive oxide (TCO). ...

Anne Le Nestour; Manuel Gaudon; Gérard Villeneuve; Marco Daturi; Ronn Andriessen; Alain Demourgues

2007-04-07T23:59:59.000Z

214

Size dependent nonlinear optical properties of YCrO{sub 3} nanosystems  

SciTech Connect (OSTI)

We report size-dependent optical limiting response of YCrO{sub 3} nanosystems upon illumination by nanosecond laser pulses at 532 nm. The limiting properties were investigated using the open aperture z-scan technique. Three-photon absorption coefficient is found to increase with particle size within the range of our investigations. We propose that the obtained nonlinearity is caused by two photon absorption, followed by excited state absorption.

Krishnan, Shiji, E-mail: shijikrish@gmail.com [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam-686 560, Kerala (India); Shafakath, K.; Philip, Reji [Light and Matter Physics Group, Raman Research Institute, Bangalore- 560 080, Karnataka (India); Kalarikkal, Nandakumar, E-mail: nkkalarikkal@mgu.ac.in [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam-686 560, Kerala and Center for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam-686 560, Kerala (India)

2014-01-28T23:59:59.000Z

215

Stress-induced switching of nonlinear optical properties of linear polymers  

Science Journals Connector (OSTI)

Replacement of every other hydrogen atom in trans-polyacetylene by other atoms, such as fluorine, results in a simple linear polymer with two carbon atoms per unit cell of the polymer chain. In such polymers, dimerization can be induced or destroyed reversibly by the application of a uniaxial stress. As a consequence, the nonlinear optical properties can be switched dramatically between those of dimerized chains, which have degenerate ground states, and nondimerized chains, which have a nondegenerate ground state.

Olle Heinonen

1990-08-15T23:59:59.000Z

216

Optical Properties  

Science Journals Connector (OSTI)

This subsection deals with sensing features of various photosensors [11.1,2,3,4]. The photosensor is the terminology used for a photodetector when used for a sensing purpose. Photodetectors can b...

Tadashi Itoh Prof.; Tsutomu Araki Prof.…

2006-01-01T23:59:59.000Z

217

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.

218

Effect of Fe-ion implantation doping on structural and optical properties of CdS thin films  

Science Journals Connector (OSTI)

We report on effects of Fe implantation doping-induced changes in structural, optical, morphological, and vibrational properties of cadmium sulfide thin films. Films were implanted with 90 keV Fe+ ions at room te...

S. Chandramohan; A. Kanjilal; S. N. Sarangi; S. Majumder…

2010-06-01T23:59:59.000Z

219

E-Print Network 3.0 - aerosol wastes Sample Search Results  

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

Schwartz Proc. Aerosols and Atmospheric Optics Radiation Balance... and Visual Air Quality, Snowbird, UT, Sept. 26-30, pp. 403-409, Air and Waste Management Association... ,...

220

Simultaneous Retrieval of Effective Refractive Index and Density from Size Distribution and Light Scattering Data: Weakly-Absorbing Aerosol  

SciTech Connect (OSTI)

We propose here a novel approach for retrieving in parallel the effective density and real refractive index of weakly absorbing aerosol from optical and size distribution measurements. Here we define “weakly absorbing” as aerosol single-scattering albedos that exceed 0.95 at 0.5 um.The required optical measurements are the scattering coefficient and the hemispheric backscatter fraction, obtained in this work from an integrating nephelometer. The required size spectra come from a Scanning Mobility Particle Sizer and an Aerodynamic Particle Sizer. The performance of this approach is first evaluated using a sensitivity study with synthetically generated but measurement-related inputs. The sensitivity study reveals that the proposed approach is robust to random noise; additionally the uncertainties of the retrieval are almost linearly proportional to the measurement errors, and these uncertainties are smaller for the real refractive index than for the effective density. Next, actual measurements are used to evaluate our approach. These measurements include the optical, microphysical, and chemical properties of weakly absorbing aerosol which are representative of a variety of coastal summertime conditions observed during the Two-Column Aerosol Project (TCAP; http://campaign.arm.gov/tcap/). The evaluation includes calculating the root mean square error (RMSE) between the aerosol characteristics retrieved by our approach, and the same quantities calculated using the conventional volume mixing rule for chemical constituents. For dry conditions (defined in this work as relative humidity less than 55%) and sub-micron particles, a very good (RMSE~3%) and reasonable (RMSE~28%) agreement is obtained for the retrieved real refractive index (1.49±0.02) and effective density (1.68±0.21), respectively. Our approach permits discrimination between the retrieved aerosol characteristics of sub-micron and sub-10micron particles. The evaluation results also reveal that the retrieved density and refractive index tend to decrease with an increase of the relative humidity.

Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Berg, Larry K.; Shilling, John E.; Flynn, Connor J.; Mei, Fan; Jefferson, Anne

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Optical control of large-signal properties of millimeter-wave and sub-millimeter-wave DDR Si IMPATTs  

Science Journals Connector (OSTI)

The authors have proposed a complete large-signal (L-S) model to investigate the optical modulation of high frequency properties of double-drift region (DDR) impact avalanche transit time (IMPATT) devices operating at different millimeter-wave and sub-millimeter-wave ... Keywords: DDR IMPATT device, Flip chip, Millimeter-wave, Optical control, Sub-millimeter-wave, Top mount

Aritra Acharyya, Suranjana Banerjee, J. P. Banerjee

2014-06-01T23:59:59.000Z

222

Reliability and optical properties of LED lens plates under high temperature stress  

Science Journals Connector (OSTI)

Abstract In this investigation the thermal degradation mechanisms of Bisphenol A Polycarbonate (BPA-PC) plates at the temperature range 100–140 °C are studied. The BPA-PC plates are currently used both in light conversion carriers in LED modules and optical lenses in LED-based products. In this study BPA-PC plates are aged at elevated temperature of 100–140 °C for a period up to 3000 h. Optical and chemical properties of the thermally-aged plates were studied using UV–Vis spectrophotometer, FTIR–ATR spectrometer, and integrated sphere. The results show that increasing the thermal ageing time leads to yellowing, loss of optical properties, and decrease of the light transmission and of the relative radiant power value of BPA-PC plates. The results also depict that there is not much discoloration within the first 1500 h of thermal ageing. The rate of yellowing significantly increases at the end of this induction period. Formation of oxidation products is identified as the main mechanism of yellowing. An exponential-based reliability model is also presented to calculate the rate of degradation reaction and to predict the life-time of BPA-PC plates.

M. Yazdan Mehr; W.D. van Driel; S. Koh; G.Q. Zhang

2014-01-01T23:59:59.000Z

223

E-Print Network 3.0 - aerosol lidar profilometer Sample Search...  

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

CLASIC Summary: Lidar RH Changes in aerosol properties and RH near clouds Airborne NASA LaRC HSRL, ARM SGP ground... ) RamanLidar RelativeHumidityRamanLidar Aerosol Extensive...

224

Investigation of the aerosol-cloud interaction using the WRF framework  

E-Print Network [OSTI]

In this dissertation, a two-moment bulk microphysical scheme with aerosol effects is developed and implemented into the Weather Research and Forecasting (WRF) model to investigate the aerosol-cloud interaction. Sensitivities of cloud properties...

Li, Guohui

2009-05-15T23:59:59.000Z

225

Optical and electronic properties of mixed Ag-Au tetramer cations  

SciTech Connect (OSTI)

We present experimental and theoretical studies of the optical response of mixed Ag {sub n} Au {sub 4?n}{sup +} (n=1–3) clusters in the photon energy range ?? = 1.9–3.5 eV. Absorption spectra are recorded by a newly built longitudinal molecular beam depletion spectroscopy apparatus providing lower limits to absolute photodissociation cross sections. The experimental data are compared to optical response calculations in the framework of long-range corrected time-dependent density functional theory with initial cluster geometries obtained by the unbiased Birmingham Cluster Genetic Algorithm coupled with density functional theory. Experiments and excited state calculations shed light on the structural and electronic properties of the mixed Ag-Au tetramer cations.

Shayeghi, A., E-mail: shayeghi@cluster.pc.chemie.tu-darmstadt.de; Schäfer, R. [Eduard-Zintl-Institut, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt (Germany)] [Eduard-Zintl-Institut, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt (Germany); Heard, C. J.; Johnston, R. L. [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)] [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

2014-02-07T23:59:59.000Z

226

High pressure studies on nanometer sized clusters: Structural, optical, and cooperative properties  

SciTech Connect (OSTI)

High-pressure Se EXAFS is used to study pressure-induced structural transformations in CdSe nanocrystals. The transformation is wurtzite to rock salt, at a pressure much higher than in bulk. High-pressure XRD is used to confirm the EXAFS results. Diffraction peak widths indicate that nanocrystals do not fragment upon transformation. Optical absorption correlates with structural transformations and is used to measure transition pressures; transformation pressure increases smoothly as nanocrystal size decreases. Thermodynamics of transformation is modeled using an elevated surface energy in the high-pressure phase. High-pressure study of Si nanocrystals show large increases in transformation pressure in crystallites to 500{angstrom} diameter, and an overall change in crystallite shape upon transformation is seen from XRD line widths. C{sub 60} single crystals were studied using Raman scattering; results provide information about the clusters` rotational state. Optical properties of high-pressure phase CdSe clusters were studied.

Tolbert, S.H.

1995-05-01T23:59:59.000Z

227

Spectral dependence of third-order nonlinear optical properties in InN  

SciTech Connect (OSTI)

We report on the nonlinear optical properties of InN measured in a wide near-infrared spectral range with the femtosecond Z-scan technique. The above-bandgap nonlinear absorption in InN is found to originate from the saturation of absorption by the band-state-filling and its cross-section increases drastically near the bandgap energy. With below-bandgap excitation, the nonlinear absorption undergoes a transition from saturation absorption (SA) to reverse-SA (RSA), attributed to the competition between SA of band-tail states and two-photon-related RSA. The measured large nonlinear refractive index of the order of 10{sup ?10} cm{sup 2}/W indicates InN as a potential material for all-optical switching and related applications.

Ahn, H., E-mail: hyahn@mail.nctu.edu.tw; Lee, M.-T.; Chang, Y.-M. [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan (China)

2014-05-19T23:59:59.000Z

228

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

SciTech Connect (OSTI)

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-Schrödinger 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.

Koc, Fatih, E-mail: fatih.koc@msn.com [Department of Physics, Faculty of Sciences, Selcuk University, 42075 Konya (Turkey); Sahin, Mehmet, E-mail: mehmet.sahin@agu.edu.tr, E-mail: mehsahin@gmail.com [Department of Physics, Faculty of Sciences, Selcuk University, 42075 Konya (Turkey); Department of Material Science and Nanotechnology Engineering, Abdullah Gül University, Kayseri (Turkey)

2014-05-21T23:59:59.000Z

229

Solvothermal synthesis and study of nonlinear optical properties of nanocrystalline thallium doped bismuth telluride  

SciTech Connect (OSTI)

Nanocrystalline Bismuth telluride and thallium (4 mol %) doped Bismuth telluride were synthesized through hydrothermal method. The as-prepared products were characterized using Powder X-ray Diffraction, High Resolution Transmission Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, UV-Visible spectroscopy and Fourier Transform Infrared Spectroscopy. Powder XRD results revealed the crystalline nature of the obtained phases. HRTEM showed the particle-like morphology of the products. The decrease in the absorption coefficient due to thallium doping was observed in FTIR spectra. The intensity dependent nonlinear optical properties of nanocrystalline bismuth telluride and thallium doped bismuth telluride were studied using the Z-scan technique in open-aperture configuration. Bismuth telluride doped with thallium showed enhanced nonlinear optical response compared to pristine bismuth telluride and hence could be used as a potential candidate for optical power limiting applications. - Graphical Abstract: Nonlinear transmission (Z-scan) curves of nanocrystalline bismuth telluride ({Delta}) and thallium doped bismuth telluride ({open_square}). Thallium doped bismuth telluride showed enhanced nonlinear absorption compared to bismuth telluride. Inset: TEM micrograph of bismuth telluride nanocrystallites. Highlights: Black-Right-Pointing-Pointer Synthesis of Nanocrystalline Bi{sub 2}Te{sub 3} and Thallium doped Bi{sub 2}Te{sub 3} through solvothermal method. Black-Right-Pointing-Pointer Reduced absorption coefficient due to thallium doping found from IR spectroscopy. Black-Right-Pointing-Pointer Open-aperture Z-scan technique for nonlinear optical studies. Black-Right-Pointing-Pointer Two photon absorption based model for theoretical fitting of Z-scan data. Black-Right-Pointing-Pointer Enhanced nonlinear absorption in Thallium doped Bi{sub 2}Te{sub 3} - potential candidate for optical power limiting applications.

Molli, Muralikrishna, E-mail: muralikrishnamolli@sssihl.edu.in [Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam-515 134 (India); Parola, Sowmendran; Avinash Chunduri, L.A.; Aditha, Saikiran; Sai Muthukumar, V; Mimani Rattan, Tanu; Kamisetti, Venkataramaniah [Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam-515 134 (India)

2012-05-15T23:59:59.000Z

230

Ultra-High Temperature Sensors Based on Optical Property Modulation and Vibration-Tolerant Interferometry  

SciTech Connect (OSTI)

The goals of the second six months of the Phase 2 of this project were to conduct first time experimental studies using optical designs and some initial hardware developed in the first 6 months of Phase 2. One focus is to modify the SiC chip optical properties to enable gas species sensing with a specific gas species under high temperature and pressure. The goal was to acquire sensing test data using two example inert and safe gases and show gas discrimination abilities. A high pressure gas mixing chamber was to be designed and assembled to achieve the mentioned gas sensing needs. Another goal was to initiate high temperature probe design by developing and testing a probe design that leads to accurately measuring the thickness of the deployed SiC sensor chip to enable accurate overall sensor system design. The third goal of this phase of the project was to test the SiC chip under high pressure conditions using the earlier designed calibration cell to enable it to act as a pressure sensor when doing gas detection. In this case, experiments using a controlled pressure system were to deliver repeatable pressure measurement data. 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 or schematics of the fabricated hardware are provided. Experimental data from the three optical sensor systems (i.e., Thickness, pressure, and gas species) 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.

Nabeel A. Riza

2006-01-26T23:59:59.000Z

231

Variation in Morphology, Hygroscopicity, and Optical Properties of Soot Particles Coated by Dicarboxylic Acids  

E-Print Network [OSTI]

particles upon coating with succinic and glutaric acids. The effective densities, fractal dimensions and dynamic shape factors of fresh and coated soot aerosol particles have been determined. Significant size-dependent increases of soot particle mobility...

Xue, Huaxin

2010-07-14T23:59:59.000Z

232

Fundamental optical properties of InN grown by epitaxial lateral overgrowth method  

SciTech Connect (OSTI)

Optical properties of InN grown by the epitaxial lateral overgrowth (ELO) method have been studied using photoluminescence (PL) and excitation-correlation (EC) measurements. The PL spectrum is analyzed by free-electron recombination band (FERB) model, which shows that the ELO sample has a very low background carrier concentration (n=5.5*10{sup 16}[cm{sup ?3]}). EC measurements show that the dependences of the band gap renormalization and Auger effect on the carrier concentrations are similar in spite of the different physical origins.

Kametani, Tatsuma; Kamimura, Jumpei; Inose, Yuta; Kunugita, Hideyuki; Kikuchi, Akihiko; Kishino, Katsumi; Ema, Kazuhiro [Department of Engineering and Applied Science, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

2013-12-04T23:59:59.000Z

233

Properties of the cladding modes of an optical fibre excited by refractive-index gratings  

SciTech Connect (OSTI)

The properties of the cladding modes of an optical fibre, excited by photoinduced long-period fibre gratings, were investigated by the near- and far-field methods. It is shown that the cladding modes considered are of the HE{sub 1m} type. A satisfactory agreement between the experimental and calculated distributions of the electromagnetic field of the modes is demonstrated. It was found that the propagation length of a cladding mode in the unperturbed fibre reaches 1 m. (laser applications and other topics in quantum electronics)

Vasil'ev, Sergei A; Dianov, Evgenii M; Medvedkov, O I; Protopopov, V N [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Costantini, D M; Iocco, A; Limberger, H G; Salathe, R-P [Institute of Applied Optics, Swiss Federal Institute of Technology, Lausanne (Switzerland)

1999-01-31T23:59:59.000Z

234

Electronic Structure and Optical Properties of AFeO2 (A = Ag, Cu) within GGA Calculations  

Science Journals Connector (OSTI)

Electronic Structure and Optical Properties of AFeO2 (A = Ag, Cu) within GGA Calculations ... The electronic structure of delafossite type oxides AFeO2 (A = Ag, Cu) has been calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the local spin density approximation (LSDA), Perdew?Burke?Ernzerhof (PBE-GGA), and Engel?Vosko (EV-GGA) generalized-gradient approximations. ... The effective Hubbard U, Ueff, has been derived on the basis of an ab initio constraint calculation and by comparison with X-ray emission spectra. ...

Khuong P. Ong; Kewu Bai; Peter Blaha; Ping Wu

2007-01-06T23:59:59.000Z

235

Synthesis, morphology and optical properties of LaFeO{sub 3} nanospheres  

SciTech Connect (OSTI)

LaFeO{sub 3} nanospheres have been successively synthesized via hydrothermal method. Structural, morphological and optical properties of the prepared nanopowder were analyzed by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–Vis absorption spectroscopy. The UV–Vis shows strong absorption at 475 nm which has excellent visible light absorption ability. Band gap energy of the prepared nanosphere was found to be 2.60 eV. The results indicate that the LaFeO{sub 3} nanospheres prepared by this method could be a kind of photocatalytic material.

Kumar, R. Dhinesh [Crystal Growth Centre, Anna University, Chennai - 600 025 (India); Jayavel, R., E-mail: rjvel@annauniv.edu [Crystal Growth Centre, Anna University, Chennai - 600 025, India and Centre for Nanoscience and Technology, Anna University, Chennai - 600 025 (India)

2014-04-24T23:59:59.000Z

236

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

SciTech Connect (OSTI)

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.

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

2014-09-23T23:59:59.000Z

237

The near future availability of photovoltaic energy in Europe and Africa in climate-aerosol modeling experiments  

Science Journals Connector (OSTI)

Abstract The near future change in productivity of photovoltaic energy (PVE) in Europe and Africa is assessed by using the climate variables simulated by the ECHAM5-HAM aerosol-climate model, and a model for the performance of photovoltaic systems. The climate simulations are forced by green-house gases emissions from the IPCC SRES B2 scenario. In addition, different scenarios for future anthropogenic aerosols emissions are applied. Thus, the sensitivity of the future PVE productivity to changes in aerosol atmospheric burdens between 2000 and 2030 is analyzed. The analysis indicates that reductions in aerosols emissions in the near future result in an increase of global warming, and a significant response in surface solar radiation and associated PVE productivity. A statistically significant reduction in PVE productivity up to 7% is observed in eastern Europe and northern Africa, while a significant increase up to 10% is observed in western Europe and eastern Mediterranean. The changes in surface solar radiation and PVE productivity are related to global effects of aerosols reduction on the large scale circulation and associated cloud cover pattern, rather than to local effects on the atmospheric optical properties. PVE assessment is then discussed in the frame of the present situation and next decades evolution of the photovoltaic market, highlighting that the effects on productivity induced by industrial and public policies, and technological development are comparable to climate related effects. The presented results encourage the improvement and further use of climate models in assessment of future renewable energies availability.

Marco Gaetani; Thomas Huld; Elisabetta Vignati; Fabio Monforti-Ferrario; Alessandro Dosio; Frank Raes

2014-01-01T23:59:59.000Z

238

Improved solid aerosol generator  

DOE Patents [OSTI]

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.

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

1988-07-19T23:59:59.000Z

239

Tuning the Optical Properties of Mesoporous TiO2 Films by Nanoscale Engineering  

SciTech Connect (OSTI)

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.

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

2012-07-03T23:59:59.000Z

240

Solar Energy Materials & Solar Cells 92 (2008) 821829 Modeling the optical properties of WO3 and WO3SiO2 thin films  

E-Print Network [OSTI]

Solar Energy Materials & Solar Cells 92 (2008) 821­829 Modeling the optical properties of WO3 the optical response of the films in the near-UV and visible region: two interband transitions for energies E

Thirumalai, Devarajan

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

THE EFFECTS OF FLAME TEMPERATURE, PARTICLE SIZE AND EUROPIUM DOPING CONCENTRATION ON THE PROPERTIES OF Y2O3:EU PARTICLES FORMED IN A FLAME AEROSOL PROCESS  

E-Print Network [OSTI]

ix LIST OF FIGURES FIGURE Page 1 Schematic of flame spray pyrolysis apparatus... 2 O 3 :Eu 9, 10 . A number of methods may be used to synthesize Y 2 O 3 :Eu particles, including colloidal methods 11-13 , combustion in fuel-oxidizer mixture 14 , evaporation? condensation 15, 16 , furnace spray pyrolysis 17 . Flame aerosol...

Yim, Hoon

2010-07-14T23:59:59.000Z

242

BIOMASS BURNING IN THE AMAZON: LINKS BETWEEN BURNING, SCIAMACHY TRACE GASES, AND AEROSOL AND SURFACE PROPERTIES FROM THE ORAC-AATSR RETRIEVAL  

E-Print Network [OSTI]

BIOMASS BURNING IN THE AMAZON: LINKS BETWEEN BURNING, SCIAMACHY TRACE GASES, AND AEROSOL, OX1 3PU, UK 2: Science and Technology Facilities Council Rutherford Appleton Laboratory, Harwell://www.iup.uni-bremen.de/sciamachy/ · ESA (A)ATSR World Fire Atlas: http://dup.esrin.esa.it/ionia/wfa/index.asp · MODIS Fire and Thermal

Oxford, University of

243

Electronic and optical properties of Co-doped 3C-SiC from density functional calculations  

Science Journals Connector (OSTI)

Abstract Structural properties along with the electronic and optical properties of intrinsic 3C-SiC and Co doped 3C-SiC are calculated using the first principles method based on the density functional theory. The calculated results show that the Fermi level locates at the valence band maximum in the pure 3C-SiC, while it shifts to the conduction band and exhibits metal-like characteristic after Co atoms are introduced into the SiC supercell. The calculated electronic structures indicate that the number of the energy levels in upper valence band substantially increased after Co doping, which is attributed to the Co-3d states. The optical property calculation suggests that the intensity of the photoluminescence (PL) spectrum is determined by the bandgap and the location of PL peak is associated with the optical absorption.

P.L. Zhou; S.K. Zheng; Lei Ma; Jingfang He; Yan Tian; Ruqian Shi

2014-01-01T23:59:59.000Z

244

Climate impacts of carbonaceous and other non-sulfate aerosols: A proposed study  

SciTech Connect (OSTI)

In addition to sulfate aerosols, carbonaceous and other non-sulfate aerosols are potentially significant contributors to global climate change. We present evidence that strongly suggests that current assessments of the effects of aerosols on climate may be inadequate because major aerosol components, especially carbonaceous aerosols, are not included in these assessments. Although data on the properties and distributions of anthropogenic carbonaceous aerosols are insufficient to allow quantification of their climate impacts, the existing information suggests that climate forcing by this aerosol component may be significant and comparable to that by sulfate aerosols. We propose that a research program be undertaken to support a quantitative assessment of the role in climate forcing of non-sulfate, particularly carbonaceous, aerosols.

Andreae, M.O.; Crutzen, P.J. [Max Planck Institute for Chemistry, Mainz (Germany); Cofer, W.R. III; Hollande, J.M. [NASA Langley Research Center, Hampton, VA (United States). Atmospheric Sciences Division] [and others

1995-06-01T23:59:59.000Z

245

Electrical and optical properties of ZnO films sequentially implanted with P ions  

Science Journals Connector (OSTI)

ZnO thin films deposited on fused silica glass substrates were sequentially implanted with P ions in terms of different energy/fluence combinations, i.e. 150 keV/1.5 ? 1015 ions cm?2, 80 keV/5.5 ? 1014 ions cm?2 and 35 keV/2.5 ? 1014 ions cm?2, or were singly implanted with 150 keV P ions at a fluence of 1.5 ? 1015 ions cm?2. X-ray diffraction, photoluminescence, Hall effect and electrical resistivity measurements were performed to characterize the properties of the films. The results show that both the unimplanted and single-P-ion-implanted films exhibit semi-insulating properties, while the sequentially implanted film shows p-type conductivity with a low carrier concentration. After annealing at 500 °C, hole concentration increases distinctly in the sequentially implanted film, and the other films show n-type conductivity. Further increasing annealing temperature to 700 °C, all the films show large resistance. Moreover, structures and optical properties of these films have also been systematically investigated. It seems that P substitutes O (PO) and/or zinc vacancies (VZn) play an important role for p-type conductivity in sequentially implanted films.

Y H Xue; X D Zhang; Y Y Shen; D C Zhang; F Zhu; L H Zhang; C L Liu

2011-01-01T23:59:59.000Z

246

Ab-initio study of optical response properties of nonstoichiometric lithium-hydride and sodium-fluoride clusters with one- and two-excess electrons  

Science Journals Connector (OSTI)

Structural and optical response properties of Li n H n-m and NanF n-m (n = 2-6, m = 1, 2) clusters containin...

V. Bona?i?-Koutecký; J. Pittner; J. Koutecký

1997-03-01T23:59:59.000Z

247

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

SciTech Connect (OSTI)

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.

Wang, Q.; Zhao, S.; Connie, A. T.; Shih, I.; Mi, Z., E-mail: zetian.mi@mcgill.ca [Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9 (Canada); Gonzalez, T.; Andrews, M. P. [Department of Chemistry, McGill University, 801 Sherbrooke St West, Montreal, Quebec H3A 0B8 (Canada); Du, X. Z.; Lin, J. Y.; Jiang, H. X. [Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

2014-06-02T23:59:59.000Z

248

Optical  

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

Optical Optical fiber-based single-shot picosecond transient absorption spectroscopy Andrew R. Cook aÍ’ and Yuzhen Shen Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, USA Í‘Received 27 January 2009; accepted 29 May 2009; published online 17 July 2009Í’ A new type of single-shot transient absorption apparatus is described based on a bundle of optical fibers. The bundle contains 100 fibers of different lengths, each successively giving Ďł15 ps longer optical delay. Data are collected by imaging light from the exit of the bundle into a sample where it is overlapped with an electron pulse or laser excitation pulse, followed by imaging onto a charge coupled device Í‘CCDÍ’ detector where the intensity of light from each fiber is measured simultaneously. Application to both ultrafast pump-probe spectroscopy and pulse radiolysis is demonstrated. For pulse

249

Optics  

Science Journals Connector (OSTI)

Optical components such as lenses, mirrors and diffraction gratings are widely used in many inspection systems. These include not only those for visual inspection with CCD cameras, but also in areas of distanc...

C. Loughlin

1993-01-01T23:59:59.000Z

250

Optical investigation of the electrical properties of a polycrystalline–semiconductor–electrolyte interface using electroreflectance  

Science Journals Connector (OSTI)

We have investigated the low?field electrolyte electroreflectance (EER) spectra of polycrystallineelectrodeposited N–CdSe in the vicinity of the E o (A B) transitions (direct gap at ? = 0). Utilizing the properties of low?field EER we have studied the distribution of the applied ac voltage i n s i t u in the photoelectrochemical solar cell configuration: (1) By measuring the in?phase and quadrature EER signals as a function of modulation frequency f we have determined the electrical impedance Z(f) of the interface for 10 HzEER amplitude as a function of applied dc bias voltage we have found evidence for surface states which contribute to Fermi level pinning; similar evidence was not observed for s i n g l e?c r y s t a lCdSe. These techniques are of general applicability for other semiconductor interfaces with optically transparent junctions and are well suited to topographical scanning.

R. P. Silberstein; Joseph K. Lyden; Micha Tomkiewicz; Fred H. Pollak

1981-01-01T23:59:59.000Z

251

ARM - Field Campaign - Biogenic Aerosols - Effects on Clouds and Climate:  

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

govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: govCampaignsBiogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 Related Campaigns Biogenic Aerosols- Effects on Clouds and Climate 2014.02.01, Petäjä, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Biogenic Aerosols - Effects on Clouds and Climate: FIGAERO-ToF-CIMS Instrument in Hyytiala with AMF-2 2014.04.01 - 2014.06.01 Lead Scientist : Joel Thornton Description The ultimate goal of this work is to connect field and laboratory observations of organic aerosol chemical and physical properties during the nascent growth stage to the diurnal and vertical distributions of aerosol abundance measured over the boreal forest by the ARM Mobile Facility 2

252

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

SciTech Connect (OSTI)

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.

Zhou, Di; Pennec, Y.; Djafari-Rouhani, B.; Lambert, Y.; Deblock, Y.; Stiévenard, D., E-mail: didier.stievenard@isen.fr [Institut d'Electronique et de Microélectronique et de Nanotechnologies, IEMN, (CNRS, UMR 8520), Groupe de Physique, Cité scientifique, avenue Poincaré, 59652 Villeneuve d'Ascq (France); Cristini-Robbe, O. [PHLAM, UMR8523, Université de Lille 1, 59652 Villeneuve d'Asq Cedex (France); Xu, T. [Key Laboratory of Advanced Display and System Application, Shanghai University, 149 Yanchang Road, Shanghai 200072 (China); Faucher, M. [Institut d'Electronique et de Microélectronique et de Nanotechnologies, IEMN, (CNRS, UMR 8520), Groupe NAM6, Cité scientifique, avenue Poincaré, 59652 Villeneuve d'Asq (France)

2014-04-07T23:59:59.000Z

253

Optical properties of wide single-mode strip and grating loaded channel waveguides  

SciTech Connect (OSTI)

New wide single-mode strip and grating loaded (SGL) channel waveguides made of silicon nitride on the oxide buffer layer of a planar silicon-on-insulator waveguide are studied. The central 10-lm-wide strip produces a multi-mode channel waveguide and diffraction gratings with a period 0.6 lm built on the structure edges produce mode-dependent additional losses due to radiation to the surrounding medium. The optical properties of these waveguides are discussed using the results of a three-dimensional numerical simulation by the FDTD and BPM methods. It is shown that a wide SGL waveguide is quasi-single-mode one because it has a small propagation loss ({approx} 0.3 dB cm{sup -1}) for the fundamental mode and a high (up to -20 dB cm{sup -1}) loss for the higher order modes. The new SGL waveguides are CMOS compatible and can become basic for fabricating new photonic elements, including tunable optical filters and multi-plexers based on the multireflector technology. (waveguides)

Tsarev, Andrei V [Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

2009-12-31T23:59:59.000Z

254

Local-field effects and the ir optical properties of ternary semiconductor alloys  

Science Journals Connector (OSTI)

We present a calculation of the infrared dielectric function of a three-dimensional ternary semiconductor alloy AB1-xCx. The diagonal disorder (masses) is treated in the coherent potential approximation; the off-diagonal disorder (force constants) as well as all the electronic properties (background dielectric constant, electronic screening) is handled by the virtual-crystal approximation. We use a nearest-neighbor single-force-constant potential which is shown to be sufficient to account for the optical properties. With the data of Ga1-xAlxAs, the calculated density of states shows one acoustic band and two optical bands, one near the gap mode of Ga in AlAs, and the other near the localized mode of Al in GaAs. Particular attention has been given to the local-field effects caused by the ionic and electronic polarization and by the screening due to the electronic delocalization. The line broadening induced by the disorder forces one to make a precise definition of the longitudinal and transverse frequencies. In addition to the well-known two-mode behavior of Ga1-xAlxAs, the model predicts a third very weak mode (about a hundred times weaker), which is a disorder-activated zone-edge mode. The model also predicts a rapid variation of the longitudinal-transverse splitting of the two main modes when one approaches the pure-crystal limit. The numerical results agree well with the experimental data and are also compared with those of the linear diatomic chain.

R. Bonneville

1981-08-15T23:59:59.000Z

255

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect (OSTI)

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.

Ruiz, D. E.; Fisch, Nathaniel

2014-02-24T23:59:59.000Z

256

Development of Aerosol Models for Radiative Flux Calculations at ARM Sites: Utility of Trajectory Clustering for Characterizing Aerosol Climatology  

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

Development of Aerosol Models for Radiative Flux Development of Aerosol Models for Radiative Flux Calculations at ARM Sites: Utility of Trajectory Clustering for Characterizing Aerosol Climatology E. Andrews Cooperative Institute for Research in the Environment University of Colorado Boulder, Colorado E. Andrews, J. A. Ogren, P. J. Sheridan, and J. M. Harris Climate Monitoring and Diagnostics Laboratory National Oceanic and Atmospheric Administration Boulder, Colorado P. K. Quinn Pacific Marine Environmental Laboratory National Oceanic and Atmospheric Administration Seattle, Washington Abstract The uncertainties associated with assumptions of generic aerosol properties in radiative transfer codes are unknown, which means that these uncertainties are frequently invoked when models and

257

ARM - Measurement - Aerosol absorption  

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

absorption 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 process in which radiation energy is retained by aerosols. 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 recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument

258

ARM - Measurement - Aerosol concentration  

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

concentration concentration 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 concentration A measure of the amount of aerosol particles (e.g. number, mass, volume) per unit volume of air. 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 recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer CPC : Condensation Particle Counter IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) TDMA : Tandem Differential Mobility Analyzer

259

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

SciTech Connect (OSTI)

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.

Mario Agio

2002-12-31T23:59:59.000Z

260

Electrical, optical, and thermal properties of Sn-doped phase change material Ge2Sb2Te5  

Science Journals Connector (OSTI)

In this article, effect of Sn on the electrical, optical, and thermal properties of Ge2Sb2Te5 is studied. Ge2Sb2Te5, Ge1.55Sb2Te5Sn0.45, and Ge1.1Sb2Te5Sn0.9...alloys are prepared by melt quenching technique and ...

Gurinder Singh; Aman Kaura; Monika Mukul; S. K. Tripathi

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Effects of temperature on the optical and electrical properties of ZnO nanoparticles synthesized by sol-gel method  

Science Journals Connector (OSTI)

ZnO nanoparticles for different thermal treatment temperatures were prepared by using sol-gel method under supercritical drying of ethyl alcohol. The structural properties showed that the ZnO nanoparticles exhibit hexagonal wurtzite structure. Thus, ... Keywords: Electrical conductivity, Nanoparticles, Optical materials, Sol-gel, Zinc oxide

K. Omri, I. Najeh, R. Dhahri, J. El Ghoul, L. El Mir

2014-10-01T23:59:59.000Z

262

Development of a device for the measurement of biological tissue optical properties using the single Monte Carlo method  

E-Print Network [OSTI]

A honeycomb probe was designed to measure the optical properties of biological tissues using single Monte Carlo method. The ongoing project is intended to be a multi-wavelength, real time, and in-vivo technique to detect breast cancer. Preliminary...

Bendele, Travis Henry

2013-02-22T23:59:59.000Z

263

Carbonaceous Aerosols and Radiative...  

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

and absorption of light by aerosols. At the ground sites, a new Humidigraph, a Cloud Condensation Nuclei Counter, a Scanning Mobility Particle Sizer, and an upgraded 915-MHz...

264

Structural, optical, and spin properties of hydrogenated amorphous silicon?germanium alloys  

Science Journals Connector (OSTI)

We report on a detailed study of structural and electronic properties of hydrogenated amorphous silicon?germanium alloys deposited by rf glow discharge from SiH4 and GeH4 in a diode reactor. The chemical composition of the alloys is related to the deposition conditions with special emphasis on preferential incorporation of Ge into the solid phase and on the role of inert dilutant gases. Hydrogen bonding in the alloys is investigated with nuclear magnetic resonance and vibrational (Raman and infrared) spectroscopy. The optical properties of a?SiGe:H samples deposited under optimal conditions are analyzed with the help of subgap absorption measurements and band?tail luminescence for the entire range of alloy composi?tions. A large part of the article describes an investigation of the electron?spin?resonance response of undoped alloys. The spin density associated with dangling bond defects localized on Si and Ge atoms has been measured as a function of alloy composition for optimized material. In addition the dependence of the two defect densities on the detailed deposition conditions (rf power substrate temperature and dilution) has been determined in a systematic way for alloys deposited from a plasma with a fixed SiH4/GeH4ratio. The results of this study especially the preferential creation of Gedangling bonds are discussed in the context of our structural data. Furthermore spin resonance is employed to investigate the light?induced degradation (Staebler–Wronski effect) of a?SiGe:H. Finally the changes of the spin?resonance spectra of a?Si0.7Ge0.3 :H upon substitutional doping with phosphorus and boron have been obtained experimentally and are used to construct a model for the electronic density of states in this material.

M. Stutzmann; R. A. Street; C. C. Tsai; J. B. Boyce; S. E. Ready

1989-01-01T23:59:59.000Z

265

BNL | Aerosol Lifecycle IOP  

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

Program Program Aerosol Life Cycle IOP The primary objectives that make up the Aerosol Life Cycle IOP can be broken down into three categories: Scientific; Logistical; and GVAX preparation. Scientific Objectives The science goals are to conduct intensive aerosol observations in a region exposed to anthropogenic, biogenic, and marine emissions with atmospheric processing times depending on air mass trajectories and time of day. Take advantage of new instruments in the MAOS (e.g., SP2, HR-PTRMS, ACSM, Trace Gas Suite, PASS-3, Aethelometer, UHSAS). Within this broad umbrella are embedded three main foci: Aerosol light absorption: How does the aerosol mass absorption coefficient (absorption per unit mass of BC) vary with atmospheric processing? Do observations agree with a shell-core model?

266

Gamma Radiation Effects on Physical, Optical, and Structural Properties of Binary As-S glasses  

SciTech Connect (OSTI)

Gamma radiation induces changes in physical, optical, and structural properties in chalcogenide glasses., Previous research has focused on As{sub 2}S{sub 3} and families of glasses containing Ge. For the first time, we present composition and dose dependent data on the As-S binary glass series. Binary As{sub x}S{sub 100-x} (x = 30, 33, 36, 40, and 42) glasses were irradiated with gamma radiation using a {sup 60}Co source at 2.8 Gy/s to accumulated doses of 1, 2, 3, and 4 MGy. The irradiated samples were characterized at each dose level for density, refractive index, x-ray diffraction, and Raman spectrum. These results are compared to those of as-made and 1 year aged samples. We report an initial increase in density followed by a decrease as a function of dose that contradicts the expected compositional dependence of molar volume of these glasses. This unusual behavior is explained based on microvoid formation and nanoscale phase-separation induced by the irradiation in these glasses. XRD, Raman, and EPR data provide supporting evidence, underscoring the importance of optimally- or overly-constrained structures for stability under aging or irradiation.

Sundaram, S. K.; McCloy, John S.; Riley, Brian J.; Murphy, Mark K.; Qiao, Hong (Amy) [Amy; Windisch, Charles F.; Walter, Eric D.; Crum, Jarrod V.; Golovchak, Roman; Shpotyuk, O.

2012-03-01T23:59:59.000Z

267

Accurate calculations of Sr properties for a high-accuracy optical clock  

E-Print Network [OSTI]

We have carried out calculations towards the goal of reducing the inaccuracy of the Sr optical atomic clock to 1$\\times10^{-17}$ and below. We calculated a.c. polarizabilities of the $5s^2 ^1S_0$ and $5s5p ^3P_0^o$ clock states that are important for reducing the uncertainty of blackbody radiation-induced frequency shifts for the $^1S_0 - ^3P_0^o$ clock transition. We determined four low-lying even-parity states whose total contribution to the static polarizability of the $^3P_0^o$ clock state is at the level of 90%. We show that if the contribution of these states is experimentally known with 0.1% accuracy, the same accuracy can be achieved for the total polarizability of the $^3P_0^o$ state. The corresponding uncertainty for the blackbody shift at a fixed room temperature will be below 1$\\times10^{-17}$. The calculations are confirmed by a number of experimental measurements on various Sr properties.

S. G. Porsev; Andrew D. Ludlow; Martin M. Boyd; Jun Ye

2008-07-09T23:59:59.000Z

268

Optical Properties of 3D Printable Plastics in the THz Regime and their Application for 3D Printed THz Optics  

Science Journals Connector (OSTI)

We characterize the terahertz (THz) properties of several materials which can be used for fused material deposition 3D printing. We identify Polystyrene as a material which ... compromise between printability and...

S. F. Busch; M. Weidenbach; M. Fey…

2014-10-01T23:59:59.000Z

269

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]

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.

Kosc, Tanya Z. (Rochester, NY); Marshall, Kenneth L. (Rochester, NY); Jacobs, Stephen D. (Pittsford, NY)

2006-05-09T23:59:59.000Z

270

Aerosol Retrievals under Partly Cloudy Conditions: Challenges and Perspectives  

SciTech Connect (OSTI)

There are lots of interesting and intriguing features of aerosols near clouds – many of which can be quite engaging, as well being useful and climate-related. Exploring aerosol with the aid of the remote sensing, in situ observations and numerical modeling has piqued our curiosity and led to improve insights into the nature of aerosol and clouds and their complex relationship. This chapter conveys the outstanding issues of cloudy-sky aerosol retrievals of important climate properties and outlines their fruitful connections to other research areas such as in situ measurements and model simulations. The chapter focuses mostly on treating the inverse problems in the context of the passive satellite remote sensing and how they can improve our understanding of the cloud-aerosol interactions. The presentation includes a basis in the inverse problem theory, reviews available approaches and discusses their applications to partly cloudy situations. Potential synergy of observations and model simulations is described as well.

Kassianov, Evgueni I.; Ovchinnikov, Mikhail; Berg, Larry K.; Flynn, Connor J.

2011-06-01T23:59:59.000Z

271

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

SciTech Connect (OSTI)

Oblique angle deposited optical thin films have attracted recent researcher’s 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.

Sarkar, P., E-mail: piyali.sarkar4@gmail.com; Tokas, R. B., E-mail: piyali.sarkar4@gmail.com; Jena, S., E-mail: piyali.sarkar4@gmail.com; Thakur, S., E-mail: piyali.sarkar4@gmail.com; Sahoo, N. K., E-mail: piyali.sarkar4@gmail.com [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2014-04-24T23:59:59.000Z

272

Influence of implantation induced Ni-doping on structural, optical, and morphological properties of nanocrystalline CdS thin films  

Science Journals Connector (OSTI)

Ni-doped CdS thin films were prepared by 90 keV Ni+ implantation at room temperature. Ni-ion implantation induced modifications in structural, optical, and morphological properties are studied for a wide range of impurity concentrations (1.86–10.19 at.%). Addition of Ni+ ions does not lead to any structural phase transformation or formation of metallic clusters or secondary phase precipitates. However, it induces structural disorder leading to a reduction in the optical band gap from 2.39 to 2.28 eV following Ni implantation up to 3 × 1016 ions cm?2. This is addressed on the basis of band tailing due to the creation of localized energy states and implantation induced grain growth. Moreover, Ni-doping is found to modify the luminescence properties by creating shallow acceptor states.

S. Chandramohan; T. Strache; S.N. Sarangi; R. Sathyamoorthy; T. Som

2010-01-01T23:59:59.000Z

273

Improvements in the structural and optical properties of a-Si:H by a dense plasma focus  

Science Journals Connector (OSTI)

Abstract Crystallization of hydrogenated amorphous silicon thin films with irradiation by using a dense plasma focus ion beam source has been investigated. The effects of the energetic ion beam irradiation on the surface morphological, structural and optical properties of the as-prepared a-Si:H thin films were investigated with field emission scanning electron microscopy, high resolution transmission electron microscopy, Raman scattering spectroscopy and mapping, and photoluminescence (PL) spectroscopy. The results show that irradiation of the energetic ion beam leads to the agglomeration of the Si grains with formation of Si nanocrystallites embedded within the amorphous matrix. This significantly enhances the optical properties of the film that it exhibits a wide range of PL emission spectra at room temperature.

Boon Tong Goh; Siew Kien Ngoi; Seong Ling Yap; Chiow San Wong; Saadah Abdul Rahman

2013-01-01T23:59:59.000Z

274

Aerosol Cans? -Aerosol cans use a pressurized  

E-Print Network [OSTI]

? - The waste generated in the processing of images/photos contains silver. Silver is a toxic heavy metal the product. Propellants are often flammable and/or toxic. Therefore, never store aerosol cans near ignition of this pamphlet. -Carefully transfer the old paint thinner from the one gallon closable can to the 30 gallon metal

Jia, Songtao

275

Optical properties are an important way to understand how climate change is altering the oceans we rely on. Dr David Antoine leads the BIOCAREX project in improving analysis of optical  

E-Print Network [OSTI]

outline the context from which the BIO-optics and CARbon EXperiment (BIOCAREX) emerged? The project grew rely on. Dr David Antoine leads the BIOCAREX project in improving analysis of optical properties. Here the intensity of light in various spectral domains, hence the changes in water colour. Do you foresee any

Antoine, David

276

Electronic and optical properties of TiCoSb under different pressures  

SciTech Connect (OSTI)

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.

Xu Bin, E-mail: hnsqxb@163.com [Department of Mathematics and Information Sciences, North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450011 (China); Zhang Jing [Department of Mathematics and Information Sciences, North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450011 (China); Liang Jianchu [Department of electronic science, Huizhou University, Guangdong 516001 (China); Gao Guoying; Yi Lin [Department of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-08-15T23:59:59.000Z

277

Direct and semidirect aerosol effects of Southern African biomass burning aerosol  

SciTech Connect (OSTI)

The direct and semi-direct radiative effects of biomass burning aerosols from Southern African fires during July-October are investigated using 20 year runs of the Community Atmospheric Model (CAM) coupled to a slab ocean model. The aerosol optical depth is constrained using observations in clear skies from MODIS and for aerosol layers above clouds from CALIPSO. Over the ocean, where the absorbing biomass burning aerosol layers are primarily located above cloud, negative top of atmosphere (TOA) semi-direct radiative effects associated with increased low cloud cover dominate over a weaker positive all-sky direct radiative effect (DRE). In contrast, over the land where the aerosols are often below or within cloud layers, reductions in cloud liquid water path (LWP) lead to a positive semi-direct radiative effect that dominates over a near-zero DRE. Over the ocean, the cloud response can be understood as a response to increased lower tropospheric stability (LTS) which is caused both by aerosol absorptive warming in overlying layers and surface cooling in response to direct aerosol forcing. The ocean cloud changes are robust to changes in the cloud parameterization (removal of the hard-wired dependence of clouds on LTS), suggesting that they are physically realistic. Over land where cloud cover changes are minimal, decreased LWP is consistent with weaker convection driven by increased static stability. Over the entire region the overall TOA radiative effect from the biomass burning aerosols is almost zero due to opposing effects over the land and ocean. However, the surface forcing is strongly negative requiring a reduction in precipitation. This is primarily realized through reductions in convective precipitation on both the southern and northern flanks of the convective precipitation region spanning the equatorial rainforest and the ITCZ in the southern Sahel. The changes are consistent with the low-level aerosol forced cooling pattern. The results highlight the importance of semi-direct radiative effects and precipitation responses for determining the climatic effects of aerosols in the African region.

Sakaeda, Naoko; Wood, Robert; Rasch, Philip J.

2011-06-21T23:59:59.000Z

278

ARM - Measurement - Aerosol particle size  

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

particle size particle size 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 particle size Linear size (e.g. radius or diameter) of an aerosol particle. 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 recorded for diagnostic or quality assurance purposes. Field Campaign Instruments AEROSMASSSPEC : Aerosol Mass Spectrometer CPI : Cloud Particle Imager DRI-GND : Desert Research Institute Ground-Based Aerosol Instruments DRUM-AEROSOL : Drum Aerosol Sampler AEROSOL-TOWER-EML : EML Tower based Aerosol Measurements

279

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

SciTech Connect (OSTI)

The goals of the first six months of this project were to lay the foundations for both the SiC front-end optical chip fabrication as well as the free-space laser beam interferometer designs and preliminary tests. In addition, a Phase I goal was to design and experimentally build the high temperature and pressure infrastructure and test systems that will be used in the next 6 months for proposed 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. In addition, photographs of the fabricated SiC optical chips, the high temperature & pressure test chamber instrument, the optical interferometer, the SiC sample chip holder, and signal processing data are provided. The design and experimentation results are summarized to give positive conclusions on the proposed novel high temperature optical sensor technology.

Nabeel A. Riza

2004-04-01T23:59:59.000Z

280

A World-wide Stratospheric Aerosol Layer  

Science Journals Connector (OSTI)

...Massachusetts An aerosol layer has been identified by a stratospheric balloon and aircraft aerosol collection program. Measurements...Abstract. An aerosol layer has been identified by a stratospheric balloon and aircraft aerosol collection program. Meas-urements...

Christian E. Junge; Charles W. Chagnon; James E. Manson

1961-05-12T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Investigation of the optical properties of MoS{sub 2} thin films using spectroscopic ellipsometry  

SciTech Connect (OSTI)

Spectroscopic ellipsometry (SE) characterization of layered transition metal dichalcogenide (TMD) thin films grown by vapor phase sulfurization is reported. By developing an optical dispersion model, the extinction coefficient and refractive index, as well as the thickness of molybdenum disulfide (MoS{sub 2}) films, were extracted. In addition, the optical band gap was obtained from SE and showed a clear dependence on the MoS{sub 2} film thickness, with thinner films having a larger band gap energy. These results are consistent with theory and observations made on MoS{sub 2} flakes prepared by exfoliation, showing the viability of vapor phase derived TMDs for optical applications.

Yim, Chanyoung; O'Brien, Maria; Winters, Sinéad [School of Chemistry, Trinity College Dublin, Dublin 2 (Ireland); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); McEvoy, Niall [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); Mirza, Inam; Lunney, James G. [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Duesberg, Georg S., E-mail: duesberg@tcd.ie [School of Chemistry, Trinity College Dublin, Dublin 2 (Ireland); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, Dublin 2 (Ireland)

2014-03-10T23:59:59.000Z

282

E-Print Network 3.0 - aerosol source-receptor relationships Sample...  

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

depth Summary: -continental transport Source-receptor relationships Aerosols Air quality Optical depth a b s t r a c t Our objectives... are to evaluate inter-continental...

283

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

SciTech Connect (OSTI)

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.

Kuladeep, Rajamudili; Jyothi, L.; Narayana Rao, D. [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)] [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Prakash, P.; Mayank Shekhar, S. [Center of Excellence in Lasers and Optoelectronic Sciences, International School of Photonics, Cochin University of Science and Technology, Kochi (India)] [Center of Excellence in Lasers and Optoelectronic Sciences, International School of Photonics, Cochin University of Science and Technology, Kochi (India); Durga Prasad, M. [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)] [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)

2013-12-28T23:59:59.000Z

284

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

SciTech Connect (OSTI)

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 k·p 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 Ż}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.

Kotani, Teruhisa, E-mail: kotani.teruhisa@sharp.co.jp [Advanced Technology Research Laboratories, Sharp Corporation, 2613-1 Ichinomoto-cho, Tenri, Nara 632-8567 (Japan); Institute for Nanoelectronics, Technische Universität München, Arcisstr. 21, 80333 Munich (Germany); Birner, Stefan [Institute for Nanoelectronics, Technische Universität München, Arcisstr. 21, 80333 Munich (Germany); Walter Schottky Institute, Technische Universität München, Am Coulombwall 4, 85748 Garching (Germany); Lugli, Paolo [Institute for Nanoelectronics, Technische Universität München, Arcisstr. 21, 80333 Munich (Germany); Hamaguchi, Chihiro [Advanced Technology Research Laboratories, Sharp Corporation, 2613-1 Ichinomoto-cho, Tenri, Nara 632-8567 (Japan)

2014-04-14T23:59:59.000Z

285

Correlation Between Optical Properties And Chemical Composition Of Sputter-deposited Germanium Cxide (GeOx) Films  

SciTech Connect (OSTI)

Germanium oxide (GeOx) films were grown on (1 0 0) Si substrates by reactive Direct-Current (DC) magnetron sputter-deposition using an elemental Ge target. The effects of oxygen gas fraction, ? = O2/(Ar + O2), on the deposition rate, structure, chemical composition and optical properties of GeOx films have been investigated. The chemistry of the films exhibits an evolution from pure Ge to mixed Ge + GeO + GeO2 and then finally to GeO2 upon increasing ? from 0.00 to 1.00. Grazing incidence X-ray analysis indicates that the GeOx films grown were amorphous. The optical properties probed by spectroscopic ellipsometry indicate that the effect of ? is significant on the optical constants of the GeOx films. The measured index of refraction (n) at a wavelength (?) of 550 nm is 4.67 for films grown without any oxygen, indicating behavior characteristic of semiconducting Ge. The transition from germanium to mixed Ge + GeO + GeO2 composition is associated with a characteristic decrease in n (? = 550 nm) to 2.62 and occurs at ? = 0.25. Finally n drops to 1.60 for ? = 0.50–1.00, where the films become GeO2. A detailed correlation between ?, n, k and stoichiometry in DC sputtered GeOx films is presented and discussed.

Murphy, Neil R.; Grant, J. T.; Sun, L.; Jones, J. G.; Jakubiak, R.; Shutthanandan, V.; Ramana, Chintalapalle V.

2014-03-18T23:59:59.000Z

286

Polymorphism and optical properties in [NH{sub 4}][InSe{sub 2}  

SciTech Connect (OSTI)

The solvothermal synthesis and characterization of two indium selenides with stoichiometry [NH{sub 4}][InSe{sub 2}] is described. Yellow [NH{sub 4}][InSe{sub 2}] (1), which exhibits a layered structure, was initially prepared in an aqueous solution of trans-1,4-diaminocyclohexane, and subsequently using a concentrated ammonia solution. A red polymorph of one-dimensional character, [NH{sub 4}][InSe{sub 2}] (2), was obtained using 3,5-dimethylpyridine as solvent. [NH{sub 4}][InSe{sub 2}] (1) crystallizes in the non-centrosymmetric space group Cc (a=11.5147(6), b=11.3242(6), c=15.9969(9) Ĺ and ?=100.354(3)°). The structural motif of the layers is the In{sub 4}Se{sub 10} adamantane unit, composed of four corner-linked InSe{sub 4} tetrahedra. These units are linked by their corners, forming [InSe{sub 2}]{sup ?} layers which are stacked back to back along the c-direction, and interspaced by [NH{sub 4}]{sup +}cations. The one-dimensional polymorph, (2), crystallizes in the tetragonal space group, I4/mcm (a=8.2519(16), c=6.9059 (14) Ĺ). This structure contains infinite chains of edge-sharing InSe{sub 4} tetrahedra separated by [NH{sub 4}]{sup +} cations. - Graphical abstract: Two polymorphic forms of [NH{sub 4}][InSe{sub 2}], which are yellow and red, have been prepared and their optical properties investigated. Highlights: • Two new indium selenides prepared by a solvothermal method. • Depending on synthesis conditions, two polymorphic forms of [NH{sub 4}][InSe{sub 2}] prepared. • Layered polymorph contains In{sub 4}Se{sub 10} adamantane clusters, linked by their corners. • One-dimensional polymorph contains [InSe{sub 2}]{sup ?} chains of edge-sharing tetrahedra. • Non-centrosymmetric layered polymorph shows a second harmonic generation response.

Ewing, Sarah J. [Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, Scotland EH14 4AS (United Kingdom); Woodward, David I. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Powell, Anthony V. [Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, Scotland EH14 4AS (United Kingdom); Vaqueiro, Paz, E-mail: P.Vaqueiro-Rodriguez@hw.ac.uk [Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, Scotland EH14 4AS (United Kingdom)

2013-08-15T23:59:59.000Z

287

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

SciTech Connect (OSTI)

The goals of the first six months of this project were to lay the foundations for both the SiC front-end optical chip fabrication as well as the free-space laser beam interferometer designs and preliminary tests. In addition, a Phase I goal was to design and experimentally build the high temperature and pressure infrastructure and test systems that will be used in the next 6 months for proposed 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. In addition, photographs of the fabricated SiC optical chips, the high temperature & pressure test chamber instrument, the optical interferometer, the SiC sample chip holder, and signal processing data are provided. The design and experimentation results are summarized to give positive conclusions on the proposed novel high temperature optical sensor technology. The goals of the second six months of this project were to conduct high temperature sensing tests using the test chamber and optical sensing instrument designs developed in the first part of the project. In addition, a Phase I goal was to develop the basic processing theory and physics for the proposed first sensor experimentation and data processing. All these goals have been achieved and are described in detail. Both optical experimental design process and sensed temperature are provided. In addition, photographs of the fabricated SiC optical chips after deployment in the high temperature test chamber are shown from a material study point-of-view.

Nabeel A. Riza

2004-11-10T23:59:59.000Z

288

Thermal lens study of thermo-optical properties and concentration quenching of Er3+-doped lead pyrophosphate based glasses  

SciTech Connect (OSTI)

In this work, we have used the thermal lens technique combined with conventional spectroscopy to characterize the thermo-optical properties of Er3+-doped lead pyrophosphate-based glasses. More precisely, we have investigated and quantified experimentally the fluorescence quantum efficiencies of the Er3+ levels, and we describe the role of concentration quenching effects. The fluorescence quantum efficiency of the 4I13/2 level is very high when compared to other phosphate glasses, while that of the green-coupled levels is very small. Other important photonic materials parameters, such as the thermal diffusivity and temperature coefficient of the optical path length change, were obtained and compared with those of other glass systems. The cumulative results obtained here for the Er-doped lead pyrophosphate glass show that this material is a good candidate for photonic applications with a characteristic Er3+ infrared emission around 1550 nm.

Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Rocha, U. [Grupo de Fotônica e Fluidos Complexos, Instituto de Física, Brazil; Guedes, Ilde [Universidade Federal do Ceara, Ceara, Brazil; Vermelho, M. V. D. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil; Boatner, Lynn A [ORNL; Jacinto, C. [Instituto de Fisica, Universidade Federal de Alagoas, Brazil

2012-01-01T23:59:59.000Z

289

Optical Properties of TiO2 Suspensions:? Influence of pH and Powder Concentration on Mean Particle Size  

Science Journals Connector (OSTI)

An approximated form of the hyperbolic solution of the radiation transfer equation obtained by Kubelka and Munk can be applied for optically thick media; this solution assumes a simple expression of the kind of Lambert?Beer law with two adjustable parameters from which the optical coefficients can be readily calculated. ... The external surfaces of both vessels were covered by mirror-polished aluminum sheets. ... A very easy approach is the Schuster?Schwarzschild approximation22 based on the main assumptions that (i) the scattering and absorption phenomena are properties of a continuum irradiated layer;8 (ii) the Lambert cosine law holds involving isotropic distribution of scattering;23 (iii) the particles are randomly distributed, and their size is smaller than the thickness of the layer; and (iv) the layer is subjected to diffuse radiation. ...

Sedat Yurdakal; Vittorio Loddo; Bernardí Bayarri Ferrer; Giovanni Palmisano; Vincenzo Augugliaro; Jaime Giménez Farreras; Leonardo Palmisano

2007-05-16T23:59:59.000Z

290

Use of Aeronet Aerosol Retrievals to Calculate Clear-Sky Irradiance at the Surface  

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

AERONET Aerosol Retrievals to AERONET Aerosol Retrievals to Calculate Clear-Sky Irradiance at the Surface G. L. Schuster National Aeronautics and Space Administration Langley Research Center Hampton, Virginia O. Dubovik National Aeronautics and Space Administration Goddard Space Flight Center Laboratory for Terrestrial Physics Greenbelt, Maryland Motivation The worldwide aerosol robotic network (AERONET) of ground-based radiometers was developed (in part) as a satellite validation tool (Holben et al. 1998). These sites utilize spectral sky-scanning radiometers, providing more information for aerosol retrievals than conventional sunphotometer measurements. The use of the almucantar sky radiance scans in conjunction with the aerosol optical thicknesses are the basis of the AERONET Dubovik retrievals, which provide the aerosol size

291

ARM - Field Campaign - 2006 MAX-Mex-Megacity Aerosol eXperiment - Mexico  

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

6 MAX-Mex-Megacity Aerosol eXperiment - Mexico City 6 MAX-Mex-Megacity Aerosol eXperiment - Mexico City Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2006 MAX-Mex-Megacity Aerosol eXperiment - Mexico City 2006.03.03 - 2006.03.28 Lead Scientist : Jeffrey Gaffney For data sets, see below. Description A 4-week field campaign was conducted in and downwind of Mexico City during March 2006. The Megacity Aerosol eXperiment - MEXico City (MAX-MEX) characterized aerosol formation and changes in aerosol composition, size distribution, light scattering coefficient, absorption coefficient, optical depth, soot-specific absorption, and radiative fluxes at selected vertical and horizontal locations in the outflow from a well-characterized urban core. Detailed analyses were made of the meteorological conditions during

292

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

SciTech Connect (OSTI)

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 450–1553?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.

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

2014-04-28T23:59:59.000Z

293

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

SciTech Connect (OSTI)

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.

Nabeel A. Riza

2005-07-22T23:59:59.000Z

294

Systems and methods for optically measuring properties of hydrocarbon fuel gases  

DOE Patents [OSTI]

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.

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

1998-10-13T23:59:59.000Z

295

Systems and methods for optically measuring properties of hydrocarbon fuel gases  

DOE Patents [OSTI]

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.

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

1998-10-13T23:59:59.000Z

296

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

DOE Patents [OSTI]

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.

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

1999-08-24T23:59:59.000Z

297

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

DOE Patents [OSTI]

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.

Pipino, Andrew Charles Rule (Gaithersburg, MD)

1999-11-16T23:59:59.000Z

298

Electronic structure and optical properties of the nonlinear optical crystal Pb{sub 4}O(BO{sub 3}){sub 2} by first-principles calculations  

SciTech Connect (OSTI)

Pb{sub 4}O(BO{sub 3}){sub 2} has a layered-type arrangement with optimally aligned BO{sub 3} triangles. The optical band gap is 3.317 eV obtained via the extrapolation method from the UV-vis-IR optical diffuse reflectance spectrum, consequently the absorption edge is about 374 nm. Density functional calculations using a generalized gradient approximation were utilized to investigate the electronic structures and optical properties of Pb{sub 4}O(BO{sub 3}){sub 2}. The calculated band structures show a direct gap of 2.608 eV, which is in agreement with the experimental optical band gap. A delocalized {pi} bonding of BO{sub 3} triangles and the stereo-effect of the lone pair 6s{sup 2} of lead cations are studied in electron densities. The birefringence is about 0.039-0.061 with the wavelength larger than about 375 nm. The calculated second-order susceptibility d{sub 24}=3.5 d{sub 36} (KDP) which is well consistent with the powder SHG intensity. - Graphical abstract: The density of state (DOS) show that the bottom of the valence bands is mainly derived from of the lone pair 6s{sup 2} of Pb{sup 2+}, and the top of the valence band is attributed to the hybridization orbitals from B-O groups. Calculated electronic structures indicate that the BO{sub 3} group with typical delocalization {pi} orbitals and strongly distorted lead oxygen polyhedra with highly asymmetric lobes on lead cations make a large SHG effect in Pb{sub 4}O(BO{sub 3}){sub 2}. Highlights: Black-Right-Pointing-Pointer Lone pair effect on Pb{sup 2+} and delocalization {pi} orbital in BO{sub 3} group is studied. Black-Right-Pointing-Pointer The combination of PbO{sub n} (n=3,4,5) and BO{sub 3} group makes Pb{sub 4}O(BO{sub 3}){sub 2} a large SHG effect. Black-Right-Pointing-Pointer Pb{sub 4}O(BO{sub 3}){sub 2} is a direct gap material with the gap 2.608 eV by the ab initio method. Black-Right-Pointing-Pointer The calculated birefringence is about 0.039-0.061 with the wavelength of about 375 nm. Black-Right-Pointing-Pointer The second-order susceptibility d{sub 24}=3.5d{sub 36} (KDP) in accordance with the experimental result.

Yang, Zhihua, E-mail: zhyang@ms.xjb.ac.cn [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China)] [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China); Pan, Shilie, E-mail: slpan@ms.xjb.ac.cn [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China)] [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China); Yu, Hongwei [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China) [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Lee, Ming-Hsien [Department of Physics, Tamkang University, Taipei 25137, Taiwan (China)] [Department of Physics, Tamkang University, Taipei 25137, Taiwan (China)

2013-02-15T23:59:59.000Z

299

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

SciTech Connect (OSTI)

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.

Sofronov, A. N.; Firsov, D. A.; Vorobjev, L. E.; Shalygin, V. A.; Panevin, V. Yu.; Vinnichenko, M. Ya. [St. Petersburg State Polytechnic University, Polytechnicheskaya str. 29, St. Petersburg (Russian Federation); Tonkikh, A. A. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Danilov, S. N. [University of Regensburg, Regensburg (Germany)

2013-12-04T23:59:59.000Z

300

Directional properties of polar paramagnetic molecules subject to congruent electric, magnetic and optical fields  

E-Print Network [OSTI]

We show that congruent electric, magnetic and non-resonant optical fields acting concurrently on a polar paramagnetic (and polarisable) molecule offer possibilities to both amplify and control the directionality of the ensuing molecular states that surpass those available in double-field combinations or in single fields alone. At the core of these triple-field effects is the lifting of the degeneracy of the projection quantum number $M$ by the magnetic field superimposed on the optical field and a subsequent coupling of the members of the "doubled" (for states with $M \

Sharma, Ketan

2015-01-01T23:59:59.000Z

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301

Nonlinear optical properties of ZnO/poly (vinyl alcohol) nanocomposite films  

SciTech Connect (OSTI)

Extensive studies have already been reported on the optical characteristics of ZnO/polymer nanocomposite films, using a variety of polymers including transparent polymers such as polystyrene, polymethyl methacrylate etc and many interesting results have been established regarding the non linear optical characteristics of these systems. Poly (vinyl alcohol)(PVA) is a water soluble polymer. Though the structural and optical studies of ZnO/PVA nanocomposite films have already been investigated, there are no detailed reports on the nonlinear optical characteristics of ZnO/PVA nanocomposite films, irrespective of the fact that these nanocomposite films can be synthesized using quite easy and cost effective methods. The present work is an attempt to study in detail the nonlinear optical behaviour of ZnO/PVA nanocomposite films using Z-scan technique. Highly transparent ZnO/PVA nanocomposite films were prepared from the ZnO incorporated PVA solution in water using spin coating technique. The ZnO nanoparticles were synthesized by the simple chemical route at room temperature. High-resolution transmission electron microscopy studies show that the ZnO nanoparticles are of size around 10 nm. The ZnO/PVA nanocomposite films were structurally characterized by X-ray diffraction technique, from which the presence of both PVA and ZnO in the nanocomposite was established. The optical absorptive nonlinearity in the nanocomposite films was investigated using open aperture Z-scan technique. The results indicate optical limiting type nonlinearity in the films due to two photon absorption in ZnO with efficiency more than 50%. These films also show a self defocusing type negative nonlinear refraction in closed aperture Z-scan experiment. The present studies indicate that, highly transparent and homogeneous films of ZnO/PVA nanocomposite can be obtained on glass substrates using simple methods, in a highly cost effective way, since PVA is water soluble. These nanocomposite films offer prospects of application as efficient optical limiters to protect light sensitive devices from the possible damage on exposure to high intensity radiation.

Jeeju, P. P., E-mail: jeejupp@gmail.com [Department of Physics, S N M College, Maliankara, Ernakulam, Kerala (India); Jayalekshmi, S., E-mail: jayalekshmi@cusat.ac.in [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi 682 022 (India); Chandrasekharan, K. [Department of Physics, National Institute of Technology, Calicut, Kerala (India)

2014-01-28T23:59:59.000Z

302

The interplay of structure and optical properties in individual semiconducting nanostructures  

E-Print Network [OSTI]

Semiconductor nanostructures exhibit distinct properties by virtue of nano-scale dimensionality, allowing for investigations of fundamental physics and the improvement of optoelectronic devices. Nanoscale morphological ...

Brewster, Megan Marie

2011-01-01T23:59:59.000Z

303

Effects of nitrogen on the growth and optical properties of ZnO thin films grown by pulsed laser deposition  

Science Journals Connector (OSTI)

ZnO thin films were grown using pulsed laser deposition by ablating a Zn target in various mixtures of O2 and N2. The presence of N2 during deposition was found to affect the growth of the ZnO thin films and their optical properties. Small N2 concentrations during growth led to strong acceptor-related photoluminescence (PL), while larger concentrations affected both the intensity and temperature dependence of the emission peaks. In addition, the PL properties of the annealed ZnO thin films are associated with the N2 concentration during their growth. The possible role of nitrogen in ZnO growth and annealing is discussed.

J B Cui; M A Thomas; Y C Soo; H Kandel; T P Chen

2009-01-01T23:59:59.000Z

304

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

SciTech Connect (OSTI)

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

Meskhidze, Nicholas; Zhang, Yang; Kamykowski, Daniel

2012-03-28T23:59:59.000Z

305

Ganges Valley Aerosol Experiment: Science and Operations Plan  

SciTech Connect (OSTI)

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 9–12 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 6–12 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 abundance—in 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.

Kotamarthi, VR

2010-06-21T23:59:59.000Z

306

Jankovic Aerosol Characterization.ppt  

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

Characterization, Characterization, Aerosol Characterization, Interpretation, and Interpretation, and Application of Data Application of Data NSRC Symposium NSRC Symposium July 8, 2008 John Jankovic, CIH CIH Center for Nanophase Materials Sciences Center for Nanophase Materials Sciences Aerosol Characterization, Interpretation, and Aerosol Characterization, Interpretation, and Application of Data Application of Data Department of Energy (DOE) Nanoscale Science Research Centers (NSRC) developing Approach to Nanomaterial ES&H - The CNMS Approach * Establish Exposure Control Guideline (ECG) - Characterize Aerosol * Collect and interpret data * Assign Process to a Control Band Aerosol Particle Characterization * Size distribution (geometric mean and geometric standard deviation related to either mass, surface, or number)

307

Optical properties of doped polycarbonate layers A.B. Djurisic a,*, W.L. Guo a  

E-Print Network [OSTI]

cells rarely exceeds 1%. Organic optoelectronic devices can be fabricated either by thermal evaporation. In order to design optoelectronic devices more eciently, the optical functions of each layer should materials have been receiving lots of attention recently for po- tential applications in optoelectronic

308

Tuning the optical properties of dilute nitride site controlled quantum dots  

SciTech Connect (OSTI)

We show that deterministic control of the properties of pyramidal site-controlled quantum dots (QD) could be achieved by exposing the QD layer to nitrogen precursor unsymmetrical dimethylhydrazine (UDMHy). The properties that could be tuned include an expected emission reduction in dilute nitride materials, excitonic pattern (biexciton binding energy) and improved carrier confinement potential symmetry (reduced fine-structure splitting)

Juska, G.; Dimastrodonato, V.; Mereni, L. O.; Gocalinska, A.; Pelucchi, E. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)

2013-12-04T23:59:59.000Z

309

Evolution of the optical properties of seawater influenced by the Deepwater Horizon oil spill in the Gulf of Mexico  

Science Journals Connector (OSTI)

The fluorescence excitation–emission matrix (EEM) technique coupled with parallel factor (PARAFAC) modeling and measurements of bulk organic carbon and other optical properties were used to characterize the oil components released from the Deepwater Horizon oil spill in the Gulf of Mexico and to examine the chemical evolution and transformation of oil in the water column. Seawater samples were collected from the Gulf of Mexico during October 2010 and October 2011, three months and fifteen months, respectively, after the oil spill was stopped. Together with previous results from samples collected during the oil spill in May/June 2010, these time series samples allow us to elucidate changes in the optical properties of dissolved organic matter (DOM) from the time of maximum oil impact to its recovery, 15 months after the spill. Although the oil had profoundly altered the optical properties of the DOM in the entire water column during the oil spill, naturally occurring DOM became predominant in surface waters by October 2010, three months after the spill. Anomalous DOM with high optical yields, however, still resided in deep waters even 15 months after the oil spill in October 2011, showing a persistent influence of the oil in deep waters. Based on fluorescence EEM data and PARAFAC modeling, three oil components and one natural humic-like DOM could be readily identified. The most prominent oil component had its maximum fluorescence intensity at Ex/Em 224/328 nm, and the other two centered on Ex/Em 264/324 and 232/346 nm, respectively. The humic-like DOM component had its wide emission peak from 390 to 460 nm over the excitation wavelength at ~248 nm. We hypothesized that component-2 (264/324 nm) was mostly derived from photochemical degradation and the component-3 (232/346 nm) could be a degradation product from both microbial and photochemical degradation, although both C2 and C3 are subject to degradation at different rates. The oil component ratios, such as C2/C1 and C3/C1, were closely related to degradation states of oil and can be used as a sensitive index to track the fate, transport and transformation of oil in the water column.

Zhengzhen Zhou; Laodong Guo

2012-01-01T23:59:59.000Z

310

Transport and optical properties of warm dense aluminum in the two-temperature regime: Ab initio calculation and semiempirical approximation  

SciTech Connect (OSTI)

This work is devoted to the investigation of transport and optical properties of liquid aluminum in the two-temperature case. At first optical properties, static electrical, and thermal conductivities were obtained in the ab initio calculation which is based on the quantum molecular dynamics, density functional theory, and the Kubo-Greenwood formula. Then the semiempirical approximation was constructed based on the results of our simulation. This approximation yields the dependences ?{sub 1{sub D{sub C}}}?1/T{sub i}{sup 0.25} and K?T{sub e}/T{sub i}{sup 0.25} for the static electrical conductivity and thermal conductivity, respectively, for liquid aluminum at ??=?2.70?g/cm{sup 3}, 3?kK???T{sub i}???T{sub e}???20?kK. Our results are well described by the Drude model with the effective relaxation time ??T{sub i}{sup ?0.25}. We have considered a number of other models for the static electrical and thermal conductivities of aluminum, they are all reduced in the low-temperature limit to the Drude model with different expressions for the relaxation time ?. Our results are not consistent with the models in which ??T{sub i}{sup ?1} and support the models which use the expressions with the slower decrease of the relaxation time.

Knyazev, D. V. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg. 2, Moscow 125412 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutskiy per. 9, Dolgoprudny, Moscow Region 141700 (Russian Federation); State Scientific Center of the Russian Federation—Institute for Theoretical and Experimental Physics of National Research Centre “Kurchatov Institute,” Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Levashov, P. R. [Joint Institute for High Temperatures RAS, Izhorskaya 13 Bldg. 2, Moscow 125412 (Russian Federation); Tomsk State University, Lenin Prospekt 36, Tomsk 634050 (Russian Federation)

2014-07-15T23:59:59.000Z

311

Supplementary material: On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol: Part 2-composition, hygroscopicity and  

E-Print Network [OSTI]

Supplementary material: On the impacts of phytoplankton-derived organic matter on the properties Artificial seawater without exudate Natural seawater+nutrients medium SWP with Phaeocystis exudate: OC NaCl theory Artificial seawater without exudate Natural seawater+nutrients medium SWP with E. Huxleyi

Meskhidze, Nicholas

312

The effects of cerium doping on the size, morphology, and optical properties of ?-hematite nanoparticles for ultraviolet filtration  

SciTech Connect (OSTI)

Highlights: • Possible application of cerium-doped ?-hematite as ultraviolet filter. • Nanoparticles obtained through co-precipitation technique using various cerium doping levels followed by annealing. • Comprehensive materials characterisation utilizing XRD, DSC/TGA, STEM, UV–vis spectroscopy. • Increasing cerium content reduces particle sizing and alters morphology. • Solubility of cerium in hematite seen between 5 and 10% doping, 10% cerium doping greatly enhances attenuation in ultraviolet region and increases optical bandgap. - Abstract: Metal oxide nanoparticles have potential use in energy storage, electrode materials, as catalysts and in the emerging field of nanomedicine. Being able to accurately tailor the desirable properties of these nanoceramic materials, such as particle size, morphology and optical bandgap (E{sub g}) is integral in the feasibility of their use. In this study we investigate the altering of both the structure and physical properties through the doping of hematite (?-Fe{sub 2}O{sub 3}) nanocrystals with cerium at a range of concentrations, synthesised using a one-pot co-precipitation method. This extremely simple synthesis followed by thermal treatment results in stable Fe{sub 2?x}Ce{sub x}O{sub y} nanoceramics resulting from the burning of any unreacted precursors and transformation of goethite-cerium doped nanoparticle intermediate. The inclusion of Ce into the crystal lattice of these ?-Fe{sub 2}O{sub 3} nanoparticles causes a significantly large reduction in mean crystalline size and alteration in particle morphology with increasing cerium content. Finally we report an increase optical semiconductor bandgap, along with a substantial increase in the ultraviolet attenuation found for a 10% Ce-doping concentration which shows the potential application of cerium-doped hematite nanocrystals to be used as a pigmented ultraviolet filter for cosmetic products.

Cardillo, Dean [Institute for Superconducting and Electronic Materials, AIIM Facility, University of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2500 (Australia); Konstantinov, Konstantin, E-mail: konstan@uow.edu.au [Institute for Superconducting and Electronic Materials, AIIM Facility, University of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2500 (Australia); Devers, Thierry [Centre de Recherche sur la Matičre Divisée, Institut de Physique, site de Chartres, Université d’Orléans (France)

2013-11-15T23:59:59.000Z

313

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

SciTech Connect (OSTI)

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.

Worsnop, Douglas R. [Principal Investigator

2014-07-28T23:59:59.000Z

314

aerosols and climate : uncertainties  

E-Print Network [OSTI]

contributes to creating a level playing field. (BC emissions tradeble like CO2 emissions?) OUTLINE #12;size. policy measures, is even more uncertain (emissions & their chemical fingerprint are uncertain (not just aerosol emissions, not just climate impacts) OUTLINE #12;- Standardization doesn't reduce

315

Optical anisotropy of fibrous biological tissues: analysis of the influence of structural properties  

SciTech Connect (OSTI)

The results of theoretical analysis of the optical anisotropy of multiply scattering fibrillar biological tissues based on the model of an effective anisotropic medium are compared with the experimental in vivo birefringence data for the rat derma obtained earlier in spectral polarisation measurements of rat skin samples in the visible region. The disordered system of parallel dielectric cylinders embedded into an isotropic dielectric medium was considered as a model medium. Simulations were performed taking into account the influence of a partial mutual disordering of the bundles of collagen and elastin fibres in derma on birefringence in samples. The theoretical optical anisotropy averaged over the spectral interval 550-650 nm for the model medium with parameters corresponding to the structural parameters of derma is in good agreement with the results of spectral polarisation measurements of skin samples in the corresponding wavelength range. (laser methods in biology)

Zimnyakov, D A; Sinichkin, Yu P [N.G. Chernyshevskii Saratov State University, Saratov (Russian Federation); Ushakova, O V [Saratov State Technical University, Saratov (Russian Federation)

2007-08-31T23:59:59.000Z

316

Ultra-High Temperature Sensors Based on Optical Property Modulation and Vibration-Tolerant Interferometry  

SciTech Connect (OSTI)

The goals of the Year 2006 Continuation Phase 2 three months period (April 1 to Sept. 30) of this project were to (a) conduct a probe elements industrial environment feasibility study and (b) fabricate embedded optical phase or microstructured SiC chips for individual gas species sensing. Specifically, SiC chips for temperature and pressure probe industrial applications were batch fabricated. Next, these chips were subject to a quality test for use in the probe sensor. A batch of the best chips for probe design were selected and subject to further tests that included sensor performance based on corrosive chemical exposure, power plant soot exposure, light polarization variations, and extreme temperature soaking. Experimental data were investigated in detail to analyze these mentioned industrial parameters relevant to a power plant. Probe design was provided to overcome mechanical vibrations. All these goals have been achieved and are described in detail in the report. The other main focus of the reported work is to modify the SiC chip by fabricating an embedded optical phase or microstructures within the chip to enable gas species sensing under high temperature and pressure. This has been done in the Kar UCF Lab. using a laser-based system whose design and operation is explained. Experimental data from the embedded optical phase-based chip for changing temperatures is provided and shown to be isolated from gas pressure and species. These design and experimentation results are summarized to give positive conclusions on the proposed high temperature high pressure gas species detection optical sensor technology.

Nabeel A. Riza

2006-09-30T23:59:59.000Z

317

Quantifying the Aerosol Indirect Effect Using Ground-Based Remote Sensors and Models  

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

Quantifying the Aerosol Indirect Effect Quantifying the Aerosol Indirect Effect Using Ground-Based Remote Sensors and Models G. Feingold National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado D. E. Lane Rutgers University Camden, New Jersey Q.-L. Min Atmospheric Sciences Research Center State University of New York Albany, New York Introduction The effect of aerosols on cloud microphysical and radiative properties (the "indirect effect") has the greatest uncertainty of all known climate-forcing mechanisms. Increases in aerosol concentrations result in higher concentrations of cloud condensation nuclei (CCN), increased cloud droplet concentrations, and smaller droplet sizes (Twomey 1974). A possible secondary effect is the suppression of rainfall.

318

Ultra-High Temperature Sensors Based on Optical Property Modulation and Vibration-Tolerant Interferometry  

SciTech Connect (OSTI)

The goals of the this part of the Continuation Phase 2 period (Oct. 1, 06 to March 31, 07) of this project were to (a) fabricate laser-doped SiC wafers and start testing the SiC chips for individual gas species sensing under high temperature and pressure conditions and (b) demonstrate the designs and workings of a temperature probe suited for industrial power generation turbine environment. A focus of the reported work done via Kar UCF LAMP lab. is to fabricate the embedded optical phase or doped microstructures based SiC chips, namely, Chromium (C), Boron (B) and Aluminum (Al) doped 4H-SiC, and to eventually deploy such laser-doped chips to enable gas species sensing under high temperature and pressure. Experimental data is provided from SiC chip optical response for various gas species such as pure N2 and mixtures of N2 and H{sub 2}, N{sub 2} and CO, N{sub 2} and CO{sub 2}, and N{sub 2} and CH{sub 4}. Another main focus of the reported work was a temperature sensor probe assembly design and initial testing. The probe transmit-receive fiber optics were designed and tested for electrically controlled alignment. This probe design was provided to overcome mechanical vibrations in typical industrial scenarios. All these goals have been achieved and are described in detail in the report.

Nabeel A. Riza

2007-03-31T23:59:59.000Z

319

How Physical and Chemical Properties Change Ice Nucleation Efficiency of Soot and Polyaromatic Hydrocarbon Particles  

E-Print Network [OSTI]

of laboratory experiments using an optical microscope apparatus equipped with a cooling stage to determine how chemical oxidation changes the ability of atmospheric aerosols to act as IN. Freezing temperatures are reported for aerosols composed of fresh...

Suter, Katie Ann

2012-10-19T23:59:59.000Z

320

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

SciTech Connect (OSTI)

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.

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

2014-05-13T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
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321

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to  

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

Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Aerosols in a Changing Atmosphere: From Detailed Aerosol Microphysics to Policy Applications Speaker(s): Susanne Bauer Date: December 6, 2011 - 4:00pm Location: 90-4133 Seminar Host/Point of Contact: Surabi Menon The anthropogenic increase in aerosol concentrations since preindustrial times and its net cooling effect on the atmosphere is thought to mask some of the greenhouse gas induced warming. Although the overall effect of aerosols on solar radiation and clouds is most certainly negative, some individual forcing agents and feedbacks have positive forcing effects. Recent studies have tried to identify some of those positive forcing agents and their individual emission sectors, However, understanding the net effect of multi-source emitting sectors and the involved cloud feedbacks is

322

First-principles calculations to investigate structural, electronic and optical properties of (BeTe)n/(CdS)n superlattices  

Science Journals Connector (OSTI)

Abstract Structural, electronic and optical properties of binary BeTe and CdS compounds and their (BeTe)n/(CdS)n superlattices (SLs) are investigated using the first-principles full potential linear muffin-tin orbitals method (FP-LMTO). The exchange–correlation potential is treated with the local density approximation of Perdew and Wang (LDA-PW). The ground-state properties are determined for the bulk materials (BeTe, CdS, and (BeTe)n/(CdS)n) in cubic phase. The calculated structural properties of BeTe and CdS compounds are in good agreement with available experimental and theoretical data. It is found that BeTe exhibit an indirect fundamental band gap and CdS and their superlattices (SLs) exhibit a direct fundamental band gap, which might make (BeTe)n/(CdS)n superlattices (SLs) materials promising and useful for optoelectronic applications. The fundamental band gap decreases with increasing the number of monolayer n.

L. Djoudi; M. Merabet; M. Boucharef; S. Benalia; D. Rached

2014-01-01T23:59:59.000Z

323

Priorities for In-situ Aerosol Measurements  

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

Priorities for In-situ Priorities for In-situ Aerosol Measurements Parameters * Aerosol light absorption coefficient - spectral, including UV, vis, and IR - as f(RH), and at ambient RH * Phase function - or relevant integral properties (how many?) * Ice nuclei * Scattering vs. RH, for RH>90% * CCN, as f(S, D p ) * Size distribution * Chemical composition - for determining climate forcing, vs. radiative effect Calibration * Number concentration * Size and shape * Light absorption reference method Characterization * Accuracy and precision - need well-understood error bars * Algorithm comparisons * Closure studies * Facilities for method testing - aircraft time Methods * Inlets - shattering/splashing - location on airplane - passing efficiency - inletless analyzers/samplers * Packaging - modular/portable "pods" for multiple a/c

324

Optical properties change of Ge{sub 12.5}Sb{sub 25}Se{sub 62.5} thin films by laser irradiation  

SciTech Connect (OSTI)

The thermally evaporated Ge{sub 12.5}Sb{sub 25}Se{sub 62.5} thin films of 800 nm thickness were subjected to light exposure for photo induced studies. The as-prepared and illuminated thin films were studied by X-ray diffraction, Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy. The optical band gap was increased due to photo induced effects along with the decrease in disorder. These optical properties changes are due to the change of homopolar bond densities. The core level peak shifting in XPS spectra supports the optical changes happening in the film due to light exposure.

Naik, Ramakanta [Physics Department, Utkal University, Bhubaneswar, Odisha, 751004 (India) and Physics Department, Indian Institute of Science, Bangalore, 560012 (India); Vinod, E. M.; Kumar, C.; Ganesan, R. [Physics Department, Indian Institute of Science, Bangalore, 560012 (India)

2013-02-05T23:59:59.000Z

325

Influence of Boron doping on the structural, optical and electrical properties of CdO thin films by spray pyrolysis technique  

SciTech Connect (OSTI)

Cadmium oxide and Boron (B) doped Cadmium oxide thin films were deposited using spray pyrolysis technique. The structural, morphological, electrical and optical properties of undoped and B doped CdO films are analyzed by varying the dopant concentration in the solution. The structural study shows the polycrystalline nature and cubic structure of undoped and B doped CdO thin films. Surface morphological study reveals that the grains are spherical in shape. Optical and electrical studies showed n-type semiconducting nature and optical band gap of 2.44 eV of deposited thin films.

Velusamy, P., E-mail: rampap2k@yahoo.co.in; Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin Films Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli- 620024, Tamil Nadu (India); Ramamurthi, K. [Department of Physics and Nanotechnology, Faculty of Engineering and Technology, SRM University, Kattankulathur - 603203, Tamil Nadu (India)

2014-04-24T23:59:59.000Z

326

Influence of Al doping on optical properties of CdS/PVA nanocomposites: Theory and experiment  

SciTech Connect (OSTI)

In the present work theoretical and experimental studies of aluminium doped cadmium sulphide polyvinyl alcohol (Al:CdS/PVA) nanocomposites have been carried out. Tetrahedral cluster AlCd{sub 9}S{sub 2}(SH){sub 18}]{sup 1?} has been encapsulated by small segments of polyvinyl alcohol (PVA) chains in order to simulate experimental environment of nanocomposites. Density functional theory (DFT) using local density approximation (LDA) functionals is employed to study the broadening of band gap upon ligation of nanoclusters. We have used in situ chemical route to synthesize nanocomposites. Optical band gap has been calculated from both experimental and theoretical approach.

Bala, Vaneeta, E-mail: vaneetabala@yahoo.com; Tripathi, S. K., E-mail: vaneetabala@yahoo.com; Kumar, Ranjan, E-mail: vaneetabala@yahoo.com [Department of Physics, Panjab University, Chandigarh (India)

2014-04-24T23:59:59.000Z

327

Optical properties of MFe{sub 4}P{sub 12} filled skutterudites  

SciTech Connect (OSTI)

Infrared reflectance spectroscopy measurements were made on four members of the MFe{sub 4}P{sub 12} family of filled skutterudites, with M=La, Th, Ce, and U. In progressing from M=La to U the system undergoes a metal-insulator transition. It is shown that, although the filling atom induces such dramatic changes in the transport properties of the system, it has only a small effect on lattice dynamics. We discuss this property of the compounds in the context of their possible thermoelectric applications. {copyright} {ital 1999} {ital The American Physical Society}

Dordevic, S.V.; Dilley, N.R.; Bauer, E.D.; Basov, D.N.; Maple, M.B. [Department of Physics, University of California, San Diego, La Jolla, California 92093-0319 (United States)] [Department of Physics, University of California, San Diego, La Jolla, California 92093-0319 (United States); Degiorgi, L. [Solid State Physics Laboratory HPF-F3/F18, ETH Zuerich, CH-8093 Zuerich (Switzerland)] [Solid State Physics Laboratory HPF-F3/F18, ETH Zuerich, CH-8093 Zuerich (Switzerland)

1999-10-01T23:59:59.000Z

328

CHRISTINE Code for High ResolutIon Satellite mapping of optical ThIckness and ĹNgstrom Exponent. Part I: Algorithm and code  

Science Journals Connector (OSTI)

Previously developed DTA (Differential Textural Analysis) and SMA (Satellite Mapping of Aerosols) image processing codes address aerosol optical thickness (AOT) retrieval and mapping over urban areas by applying the contrast reduction principle to single ... Keywords: Ĺngstrom, Aerosol optical thickness, Air pollution, Contrast reduction, High resolution

Nicolas I. Sifakis; Christos Iossifidis

2014-01-01T23:59:59.000Z

329

Structural, optical and electrical properties of WOxNy filmsdeposited by reactive dual magnetron sputtering  

SciTech Connect (OSTI)

Thin films of tungsten oxynitride were prepared by dual magnetron sputtering of tungsten using argon/oxygen/nitrogen gas mixtures with various nitrogen/oxygen ratios. The presence of even small amounts of oxygen had a great effect not only on the composition but on the structure of WOxNy films, as shown by Rutherford backscattering and x-ray diffraction, respectively. Significant incorporation of nitrogen occurred only when the nitrogen partial pressure exceeded 89 percent of the total reactive gas pressure. Sharp changes in the stoichiometry, deposition rate, room temperature resistivity, electrical activation energy and optical band gap were observed when the nitrogen/oxygen ratio was high.The deposition rate increased from 0.31 to 0.89 nm/s, the room temperature resistivity decreased from 1.65 x 108 to 1.82 x 10-2 ?cm, the electrical activation energy decreased from 0.97 to 0.067 eV, and the optical band gap decreased from 3.19 to 2.94 eV upon nitrogen incorporation into the films. WOxNy films were highly transparent as long as the nitrogen incorporation was low, and were brownish (absorbing) and partially reflecting as nitrogen incorporation became significant.

Mohamed, Sodky H.; Anders, Andre

2006-06-05T23:59:59.000Z

330

Optical properties of the spin-ladder compound Sr14Cu24O41  

Science Journals Connector (OSTI)

We report the measurements of the pseudodielectric function, far-infrared reflectivity, and Raman scattering spectra in Sr14Cu24O41 single crystal. We study the lattice and the spin dynamics of the Cu2O3 spin ladders and CuO2 chains of this compound. The ellipsometric and the optical reflectivity measurements yield the gap values of 1.4, 1.86, 2.34 eV (2.5 eV) for the ladders (chains) along the c axis and 2.4 eV along the a axis. The electronic structure of the Cu2O3 ladders is analyzed using the tight-binding approach for the correlated electron systems. The correlation gap value of 1.4 eV is calculated with the transfer energy (hopping) parameters t=t0=0.26 eV, along and perpendicular to legs, txy=0.026 eV (interladder hopping) and U=2.1 eV, as a Coulomb repulsion. The optical parameters of the infrared-active phonons and plasmons are obtained by an oscillator fitting procedure of the reflectivity spectra. Raman scattering spectra are measured at different temperatures using different laser line energies. The two-magnon peak is observed at about 2880 cm-1. At temperatures below 150 K the new infrared and Raman modes appear due to the charge ordering.

Z. V. Popovi?; M. J. Konstantinovi?; V. A. Ivanov; O. P. Khuong; R. Gaji?; A. Vietkin; V. V. Moshchalkov

2000-08-15T23:59:59.000Z

331

Synthesis and optical properties of IIVI 1D nanostructures Muhammad Iqbal Bakti Utama,a  

E-Print Network [OSTI]

size- and structure-dependent material properties where the relevance of quantum confinement effects Technological University, Singapore 637371. E-mail: Qihua@ntu.edu.sg b National Key Laboratory of Photoelectric, Nanyang Technological University (NTU), Singapore. Before he moved to NTU, he had been working

Xiong, Qihua

332

Preliminary laboratory studies of the optical scattering properties of the crystal clouds  

E-Print Network [OSTI]

in the earth's radiation balance and so inÂŻuence weather and climate. Solar radiation reaching the top of ice crystals at a visible wavelength in order to gain information which can be used in climate models properties of atmospheric ice in the solar and infrared spectral bands is of great importance to studies

Boyer, Edmond

333

ARM - Mobile Aerosol Observing System  

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

FacilitiesMobile Aerosol Observing System FacilitiesMobile Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments 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 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Mobile Aerosol Observing System Intensive aerosol observations conducted on the campus of Brookhaven National Laboratory on Long Island, New York, using the ARM Mobile Aerosol Observing System. Intensive aerosol observations conducted on the campus of Brookhaven

334

Optical properties across the solar spectrum and indoor thermal performance of cool white coatings for building energy efficiency  

Science Journals Connector (OSTI)

Abstract Two single-layer, waterborne cool white coatings for building envelopes were recently developed for use in improving building energy efficiency. After the coatings were manufactured, their optical properties over the solar spectrum and their indoor temperature reduction effect were systematically investigated using appropriate tools, and the advantages/disadvantages of single layer cool white coatings over multilayer ones were discussed in detail. The preparation process enables these two coatings to integrate multiple cooling principles and thereby exhibit high solar heat reflectance and good indoor temperature reduction. The predicted industrial limit of solar heat reflectance for practical reflective cool white coatings is 0.91. Use of cool white coatings significantly reduces radiant heat flux. The temperature reduction effects evaluated by a self-developed device cannot describe adequately the indoor cooling performance of cool coatings.

Zhongnan Song; Weidong Zhang; Yunxing Shi; Jianrong Song; Jian Qu; Jie Qin; Tao Zhang; Yanwen Li; Hongqiang Zhang; Rongpu Zhang

2013-01-01T23:59:59.000Z

335

Ground-state properties of a Bose-Einstein condensate tuned by a far-off-resonant optical field  

SciTech Connect (OSTI)

In this paper, we explore a scheme to tackle a challenging problem of stable Bose-Einstein condensates (BECs) with attractive atom interactions. In this scheme, the s-wave scattering length is tuned in space, rather than in time as previously studied, by a far-off-resonant Gaussian optical field, from negative to positive in the center region of the potential well. We find that this tuning leads to coexisting repulsive and attractive interactions within a single atomic gas and consequently a stable BEC in the repulsive region. We investigate the ground-state properties of the tuned BECs and show them to exhibit a strikingly different spatial density distribution from a conventional one with a positive s-wave scattering length. The tuned BEC is formed only when the condensed number is less than a critical number. We derive a formula for the critical number.

Dong Guangjiong [Physics Department, Center for Nonlinear Studies and the Beijing-Hong Kong-Singapore Joint Center for Nonlinear and Complex Systems, Hong Kong, Kowloon Tong, Hong Kong (China); Hu Bambi [Physics Department, Center for Nonlinear Studies and the Beijing-Hong Kong-Singapore Joint Center for Nonlinear and Complex Systems, Hong Kong, Kowloon Tong, Hong Kong (China); Department of Physics, University of Houston, Houston, Texas 77204-5005 (United States); Lu Weiping [Department of Physics, Heriot-Watt University, Edinburgh, Scotland (United Kingdom)

2006-12-15T23:59:59.000Z

336

Structural, electronic and optical properties of CdxZn1 ? xS alloys from first-principles calculations  

Science Journals Connector (OSTI)

Abstract Structural, electronic and optical properties as well as structural phase transitions of ternary alloy CdxZn1 ? xS have been investigated using the first-principles calculations based on the density functional theory. We found that the crystal structure of CdxZn1 ? xS alloys transforms from wurtzite to zinc blende as Cd content of x = 0.83 . Effect of Cd content on electronic structures of CdxZn1 ? xS alloys has been studied. The bandgaps of CdxZn1 ? xS alloys with wurtzite and zinc blende structures decrease with the increase of Cd content. Furthermore, dielectric constant and absorption coefficient also have been discussed in detail.

Meiling Xu; Yongfeng Li; Bin Yao; Zhanhui Ding; Gang Yang

2014-01-01T23:59:59.000Z

337

Electronic, dielectric, and optical properties of individual composite silver halide microcrystals using the EELS and LMTO-ASA techniques  

Science Journals Connector (OSTI)

The low-loss fine structure in electron energy-loss spectra (EELS) of individual composite high-aspect-ratio tabular AgX(X=Br, I) microcrystals between 4 and 26 eV was investigated by cryo-EELS and energy-filtering transmission electron microscopy. Local dielectric permittivity, refractive index, and absorption coefficient have been determined using Kramers-Kronig relationships. Quantum-mechanical calculations of the AgBr band structure and dielectric permittivity by the linear muffin-tin orbital method in the atomic spheres approximation have been used to assign the structure attributed to exciton peaks. Experimental local dielectric parameters and joint optical density of states were found to be in fair general agreement with calculated dielectric properties and densities of states.

Vladimir Oleshko; Marc Amkreutz; Harald Overhof

2003-03-17T23:59:59.000Z

338

Oxygen partial pressure influenced structural and optical properties of DC magnetron sputtered ZrO{sub 2} films  

SciTech Connect (OSTI)

Thin films of zirconium oxide (ZrO{sub 2}) were deposited on (100) p-silicon and quartz substrates by sputtering of metallic zirconium target under different oxygen partial pressures in the range 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa. The effect of oxygen partial pressure on the structural and optical properties of the deposited films was systematically investigated. The deposition rate of the films decreased from 3.3 to 1.83 nm/min with the increase of oxygen partial pressure from 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa respectively. The X-ray diffraction profiles revealed that the films exhibit (111) refection of zirconium oxide in monoclinic phase. The optical band gap of the films increased from 5.62 to 5.80 eV and refractive index increased from 2.01 to 2.08 with the increase of oxygen partial pressure from 8 Multiplication-Sign 10{sup -3}-6 Multiplication-Sign 10{sup -2}Pa respectively.

Kondaiah, P.; Madhavi, V.; Uthanna, S. [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India)

2013-02-05T23:59:59.000Z

339

A stable, quasi-2D modification of silver: optical, electronic, vibrational and mechanical properties, and first principles calculations  

Science Journals Connector (OSTI)

We report the optical, electronic, vibrational and mechanical properties of a stable, anisotropic, hexagonal (4H) form of silver. First principles calculations based on density functional theory were used to simulate the phonon dispersion curves and electronic band structure of 4H-Ag. The phonon dispersion data at 0 K do not contain unstable phonon modes, thereby confirming that it is a locally stable structure. The Fermi surface of the 4H phase differs in a subtle way from that of the cubic phase. Experimental measurements indicate that, when compared to the commonly known face-centered cubic (3C) form of silver, the 4H-Ag form shows a 130-fold higher, strongly anisotropic, in-plane resistivity and a much lower optical reflectance with a pronounced surface plasmon contribution that imparts a distinctive golden hue to the material. Unlike common silver, the lower symmetry of the 4H-Ag structure allows it to be Raman active. Mechanically, 4H-Ag is harder, more brittle and less malleable. Overall, this novel, poorly metallic, anisotropic, darker and harder crystallographic modification of silver bears little resemblance to its conventional counterpart.

Indrani Chakraborty; Sharmila N Shirodkar; Smita Gohil; Umesh V Waghmare; Pushan Ayyub

2014-01-01T23:59:59.000Z

340

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

SciTech Connect (OSTI)

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.

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

2009-01-23T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Controlled synthesis and optical properties of BaFBr:Eu{sup 2+} crystals via ethanol/water solutions  

SciTech Connect (OSTI)

Graphical abstract: A facile and cost-effective approach for the controlled synthesis of BaFBr:Eu{sup 2+} crystals is introduced. The structures and morphologies of the obtained products are affected by the amount of water and ethanol in the solvent mixtures. Highlights: ? Precipitation route for preparing BaFBr nano and micro crystals in water/ethanol solvent mixtures. ? Controlled growth of BaFBr nano crystals by tuning the volume ratio of Ethanol/water. ? Luminescence properties after annealing at 200 °C are investigated. ? Short lifetimes of photoluminescence and photostimulated luminescence in BaFBr:Eu{sup 2+} nano crystals are presented. ? Shortened lifetimes in BaFBr:Eu{sup 2+} nano crystals demonstrate that they are promising materials for use in X-ray imaging systems. -- Abstract: BaFBr:Eu{sup 2+} crystals with different structures were successfully fabricated via a simple precipitation method using ethanol/water mixtures as solvents. The amount of ethanol in the solvent mixtures played a significant role in the formation of final products, enabling the well-controlled growth of the BaFBr crystals. A possible formation mechanism was proposed based on the results of controlled experiments. The phases and morphologies of the resulting samples were systematically investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED) and elementary analysis. The optical properties of the annealed BaFBr:Eu{sup 2+} nano-cuboids were investigated using photoluminescence (PL), photo-stimulated luminescence spectroscopy (PSL) and kinetic decays. Faster decay behaviors demonstrate that these BaFBr:Eu{sup 2+} phosphors are promising materials for applications in optical storage fields. Furthermore, it is envisaged that this environmentally benign method can be extended to prepare other fluoride halides.

Liang, Qinghua [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China) [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 10039 (China); Li, Zhi, E-mail: lizhi@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China)] [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China); Ma, Wangjing; Shi, Yao [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China)] [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China); Yang, Xinmin, E-mail: xmyang@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China)] [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), 29 zhongguancun East Road, Beijing 100190 (China)

2012-09-15T23:59:59.000Z

342

Experimental study of nuclear workplace aerosol samplers  

E-Print Network [OSTI]

LITERATURE REVIEW Aerosol Losses in an Inlet . Aerosol Losses in a Transport System Aerosol Losses in CAMs Critical Flow Venturi 8 13 15 16 EXPERIMENT PROCEDURE 18 CAM Evaluation Consideration FAS Evaluation Consideration Test Protocol Mixing... Chamber Setup High Speed Aerosol Wind Tunnel Setup Low Speed Aerosol Wind Tunnel Setup Critical Flow Venturi 18 19 21 22 24 25 27 RESULTS AND DISCUSSION Page 28 Aerosol Penetration through Transport Systems and CAM Areal Uniformity Deposits...

Parulian, Antony

2012-06-07T23:59:59.000Z

343

ARM - PI Product - Aerosol Retrievals from ARM SGP MFRSR Data  

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

ProductsAerosol Retrievals from ARM SGP MFRSR Data ProductsAerosol Retrievals from ARM SGP MFRSR 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 : Aerosol Retrievals from ARM SGP MFRSR Data 2000.01.01 - 2000.12.31 Site(s) SGP General Description 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

344

EMSL: Science: Atmospheric Aerosol Systems  

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

Atmospheric Aerosol Systems Atmospheric Aerosol Systems atmospheric logo Nighttime enhancement of nitrogen-containing organic compounds, or NOC Observed nighttime enhancement of nitrogen-containing organic compounds, or NOC, showed evidence of being formed by reactions that transform carbonyls into imines. The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model parameterization to improve the accuracy of climate model simulations and develop a predictive understanding of climate. By elucidating the role of natural and anthropogenic regional and global climate forcing mechanisms, EMSL can provide DOE and others with the ability to develop cost-effective strategies to monitor, control and mitigate them.

345

Two-Column Aerosol Project  

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

help find the answer, the Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility is conducting the Two-Column Aerosol Project (TCAP) at Cape Cod...

346

ARM Cloud Aerosol Precipitation Experiment  

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

Satellite Observation CAS Cloud Aerosol Spectrometer CCN Cloud Condensation Nuclei CIP Cloud Imaging Probe CPC Condensation Particle Counter CSPHOT Cimel sunphotometer CVI...

347

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

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

ARM, Two Columns and a Whole Lot of Aerosols 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 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.

348

Optical properties of single ZnTe nanowires grown at low temperature  

SciTech Connect (OSTI)

Optically active gold-catalyzed ZnTe nanowires have been grown by molecular beam epitaxy, on a ZnTe(111) buffer layer, at low temperature (350 °C) under Te rich conditions, and at ultra-low density (from 1 to 5 nanowires per ?m{sup 2}). The crystalline structure is zinc blende as identified by transmission electron microscopy. All nanowires are tapered and the majority of them are <111> oriented. Low temperature micro-photoluminescence and cathodoluminescence experiments have been performed on single nanowires. We observe a narrow emission line with a blue-shift of 2 or 3 meV with respect to the exciton energy in bulk ZnTe. This shift is attributed to the strain induced by a 5 nm-thick oxide layer covering the nanowires, and this assumption is supported by a quantitative estimation of the strain in the nanowires.

Artioli, A.; Stepanov, P.; Den Hertog, M.; Bougerol, C.; Genuist, Y.; Donatini, F.; André, R.; Nogues, G.; Tatarenko, S.; Ferrand, D.; Cibert, J. [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France) [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France); Inst NEEL, CNRS, F-38042 Grenoble (France); Rueda-Fonseca, P. [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France) [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France); Inst NEEL, CNRS, F-38042 Grenoble (France); INAC, CEA and Université de Grenoble, 17 rue des Martyrs, 38054 Grenoble (France); Bellet-Amalric, E.; Kheng, K. [INAC, CEA and Université de Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)] [INAC, CEA and Université de Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)

2013-11-25T23:59:59.000Z

349

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

SciTech Connect (OSTI)

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.

Kumar, N. Manoj, E-mail: manukokkal01@gmail.com; Rao, G. Venkateswara, E-mail: manukokkal01@gmail.com; Akhila, B. E., E-mail: manukokkal01@gmail.com; Shashikala, H. D., E-mail: manukokkal01@gmail.com [Department of Physics, National Institute of Technology Karnataka, Surathkal, Srinivasnagar -575025, Karnataka (India)

2014-04-24T23:59:59.000Z

350

Nonlinear-optical and structural properties of nanocrystalline silicon carbide films  

SciTech Connect (OSTI)

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.

Brodyn, M. S.; Volkov, V. I., E-mail: volkov@iop.kiev.ua; Lyakhovetskii, V. R.; Rudenko, V. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine); Puzilkov, V. M.; Semenov, A. V. [National Academy of Sciences of Ukraine, Institute of Monocrystals (Ukraine)

2012-02-15T23:59:59.000Z

351

Nanocystals of Hematite with Unconventional Shape-Truncated Hexagonal Bipyramid and Its Optical and Magnetic Properties  

Science Journals Connector (OSTI)

The crystal structure of the material was examined with X-ray diffraction on a Rigaku miniFlex-II desktop X-ray diffractometer, Cu K? radiation with ? = 0.154056 nm. ... The electronic transition occuring in the optical absorption spectra of Fe3+substance includes three types:(34) (1) the Fe3+ ligand field transition or the d–d transitions, (2) the ligand–metal charge-transfer transitions, and (3) the pair excitations of two adjacent Fe3+ cations that are magnetically coupled. ... The morphologies at nanoscale are relevant to the control of shapes and sizes, surface chem., and performance of these nanoparticles, as well as our understanding of naturally occurring processes. ...

Thanh-Khue Van; Hyun Gil Cha; Cuong Ky Nguyen; Soo-Whan Kim; Myun-Hwa Jung; Young Soo Kang

2012-01-03T23:59:59.000Z

352

Growth and optical properties of CdTe quantum dots in ZnTe nanowires  

SciTech Connect (OSTI)

We report on the formation of optically active CdTe quantum dots in ZnTe nanowires. The CdTe/ZnTe nanostructures have been grown by a gold nanocatalyst assisted molecular beam epitaxy in a vapor-liquid solid growth process. The presence of CdTe insertions in ZnTe nanowire results in the appearance of a strong photoluminescence band in the 2.0 eV-2.25 eV energy range. Spatially resolved photoluminescence measurements reveal that this broad emission consists of several sharp lines with the spectral width of about 2 meV. The large degree of linear polarization of these individual emission lines confirms their nanowire origin, whereas the zero-dimensional confinement is proved by photon correlation spectroscopy.

Wojnar, Piotr; Janik, Elzbieta; Baczewski, Lech T.; Kret, Slawomir; Karczewski, G.; Wojtowicz, Tomasz [Institute of Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warsaw (Poland); Goryca, Mateusz; Kazimierczuk, Tomasz; Kossacki, Piotr [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul Hoza 69, 00-681 Warsaw (Poland)

2011-09-12T23:59:59.000Z

353

Enhanced optical property in quaternary GaInAsSb/AlGaAsSb quantum wells  

SciTech Connect (OSTI)

High quality GaInAsSb/AlGaAsSb quantum wells (QWs) have been grown by molecular beam epitaxy using proper interface treatments. By controlling the group-V elements at interfaces, we obtained excellent optical quality QWs, which were free from undesired localized trap states, which may otherwise severely affect the exciton recombination. Strong and highly efficient exciton emissions up to room temperature with a wavelength of 2.2 ?m were observed. A comprehensive investigation on the QW quality was carried out using temperature dependent and power dependent photoluminescence (PL) measurements. The PL emission intensity remains nearly constant at low temperatures and is free from the PL quenching from the defect induced localized states. The temperature dependent emission energy had a bulk-like behavior, indicating high quality well/barrier interfaces. Because of the uniformity of the QWs and smooth interfaces, the low temperature limit of inhomogeneous line width broadening is as small as 5?meV.

Lin, Chien-Hung, E-mail: chlin.ee97g@g2.nctu.edu.tw; Lee, Chien-Ping [Department of Electronics Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

2014-10-21T23:59:59.000Z

354

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

SciTech Connect (OSTI)

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 550°C to 700°C 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.

Mishra, Rakesh K., E-mail: mishrarake@gmail.com; Kashyap, Raman, E-mail: mishrarake@gmail.com; Vedeshwar, A. G., E-mail: mishrarake@gmail.com; Tandon, R. P., E-mail: mishrarake@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 1-10007 (India)

2014-04-24T23:59:59.000Z

355

Molecular Characterization of Biomass Burning Aerosols Using...  

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

Biomass Burning Aerosols Using High Resolution Mass Spectrometry. Molecular Characterization of Biomass Burning Aerosols Using High Resolution Mass Spectrometry. Abstract: Chemical...

356

In-situ measurements of the mixing state and optical properties of soot with implications for radiative forcing estimates  

Science Journals Connector (OSTI)

...of fresh soot emissions from diesel trucks (24). Temporal Characteristics...Asian climate and hydrological cycle . Proc Natl Acad Sci USA 102 : 5326...Edwards JM Shine KP ( 1997 ) General circulation model calculations of the direct...mode particles from heavy duty diesel vehicles using aerosol time-of-flight...

Ryan C. Moffet; Kimberly A. Prather

2009-01-01T23:59:59.000Z

357

Aerosol mass spectrometry systems and methods  

DOE Patents [OSTI]

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.

Fergenson, David P.; Gard, Eric E.

2013-08-20T23:59:59.000Z

358

Structural and optical properties of wood and wood finishes studied using optical coherence tomography: application to an 18th century Italian violin  

Science Journals Connector (OSTI)

Optical coherence tomography (OCT) is especially attractive for the study of cultural heritage artifacts because it is noninvasive and nondestructive. We have developed an original...

Latour, Gaël; Echard, Jean-Philippe; Soulier, Balthazar; Emond, Isabelle; Vaiedelich, Stéphane; Elias, Mady

2009-01-01T23:59:59.000Z

359

Electrical and optical properties of p-type ZnO  

Science Journals Connector (OSTI)

ZnO has ideal qualities for bright, efficient UV light emitting diodes and laser diodes, based on p–n junctions. However, while high quality n-type ZnO has been available for many years, the development of good p-type material is a much more recent phenomenon. The most successful acceptor dopants have been the group V elements, N, P and As; N substitutes on the O site, but the exact structures of the P and As acceptors have not yet been established. Resistivities as low as 0.4 ? cm have been measured, and some UV heterojunction and homojunction LEDs have been fabricated. Optical fingerprints of p-type ZnO often include a photoluminescence line at 3.31 eV, and strong donor-bound exciton lines at 3.357 and 3.367 eV, both of which are well known from previous studies of n-type ZnO.

David C Look

2005-01-01T23:59:59.000Z

360

The Electric and Optical Properties of Doped Small Molecular Organic Light-Emitting Devices  

SciTech Connect (OSTI)

Organic light-emitting devices (OLEDs) constitute a new and exciting emissive display technology. In general, the basic OLED structure consists of a stack of fluorescent organic layers sandwiched between a transparent conducting-anode and metallic cathode. When an appropriate bias is applied to the device, holes are injected from the anode and electrons from the cathode; some of the recombination events between the holes and electrons result in electroluminescence (EL). Until now, most of the efforts in developing OLEDs have focused on display applications, hence on devices within the visible range. However some organic devices have been developed for ultraviolet or infrared emission. Various aspects of the device physics of doped small molecular OLEDs were described and discussed. The doping layer thickness and concentration were varied systematically to study their effects on device performances, energy transfer, and turn-off dynamics. Low-energy-gap DCM2 guest molecules, in either {alpha}-NPD or DPVBi host layers, are optically efficient fluorophores but also generate deep carrier trap-sites. Since their traps reduce the carrier mobility, the current density decreases with increased doping concentration. At the same time, due to efficient energy transfer, the quantum efficiency of the devices is improved by light doping or thin doping thickness, in comparison with the undoped neat devices. However, heavy doping induces concentration quenching effects. Thus, the doping concentration and doping thickness may be optimized for best performance.

Kwang-Ohk Cheon

2003-08-05T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Probing the properties of nebular plasmas with optical and infrared spectroscopy  

SciTech Connect (OSTI)

A number of current developments arising from spectroscopic studies of ionized nebulae are reviewed. Until the past decade or so, such studies were generally confined to the analysis of recombination lines from hydrogen and helium, along with collisionally excited forbidden lines from second and third row elements in the periodic table. However, the advent of efficient detectors on 8m-class telescopes has enabled the detection of recombination lines from second and third row elements, along with collisionally excited lines from much less abundant species. Significant discrepancies have been found between ionic abundances derived from collisionally excited lines and those obtained for the same ions from their recombination lines. The existence of 'cold plasma' with T{sub e}{<=} 1000 K has been confirmed for a number of planetary nebulae. Optical and infrared collisionally excited ionic lines from a wide range of 'neutron-capture' elements from beyond the iron abundance peak have also been detected. There is a consequent need for new calculations and experimental measurements of the atomic data needed to interpret these observations.

Barlow, M. J. [Dept. of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

2012-05-25T23:59:59.000Z

362

Structural origin of the nonlinear optical properties of lead niobium germanate film glasses  

SciTech Connect (OSTI)

The structural origin of the nonlinear optical susceptibility (/{chi}{sup (3)}/) of lead-niobium-germanate film glasses with large Nb{sub 2}O{sub 5} contents has been investigated. /{chi}{sup (3)}/ shows a strong enhancement with the Nb content in the films with /{chi}{sup (3)}/ values close to 2 x 10{sup -11} esu at 800 nm for a Nb content as high as 0.71. Boling-Glass-Owyoung and Lines' semiempirical models predict accurately the values of /{chi}{sup (3)}/ for transparent bulk glasses but not for film glasses. This discrepancy is related to the remarkable structural differences between them. Raman spectroscopy suggests the formation of a three-dimensional (3D) structure of [NbO{sub 6}] octahedra in the case of film glasses having large Nb contents, while X-ray photoelectron spectroscopy shows that a significant fraction of these units contain Nb{sup 4+} ions. The combination of a 3D structure of [NbO{sub 6}] with the presence of Nb{sup 4+} polarons and their migration through electron intervalence transfer is proposed as the origin of the observed enhancement of /{chi}{sup (3)}/ in the film glasses.

Munoz-Martin, D.; Ruiz de La Cruz, A.; Fernandez-Navarro, J. M.; Solis, J.; Gonzalo, J. [Laser Processing Group, Instituto de Optica (CSIC), Serrano 121, 28006 Madrid (Spain); Domingo, C. [Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid (Spain)

2011-07-15T23:59:59.000Z

363

Optical and electrical properties of porous silicon impregnated with Congo Red dye  

Science Journals Connector (OSTI)

Incorporation of molecules into porous silicon (PS) matrix is of particular interest for potential utilization in hybrid organic-semiconductor devices. In this study the incorporation of Congo Red molecules inside luminescent PS layers was investigated. The resulting structures have been characterized by Fourier Transformer Infrared (FTIR) and photoluminescence (PL) techniques. Based on these characterizations the infiltration of dye molecules into the porous matrix has been proved. The recuperated PL signal was more important than that of porous silicon alone. A nonradiative excitation transfer due to dipolar interactions was evidenced from the effect of the CR concentration on the PL emission which was also confirmed by FTIR spectroscopy. It was found that the formed composite displays an efficient and stable PL. Preliminary characterizations of the electrical properties of the resulting nanocomposite structure have been also performed. The current–voltage (I–V) characteristics of CR-PS/p-Si were measured at the room temperature (300?K). To study the effect of illumination on CR-PS/p-Si composites the measurement has been performed in dark and under illumination at room temperature. The diode characteristics including zero-bias barrier height (?B0) ideality factor (n) and series resistance (Rs) were calculated at room temperature in dark and under illumination. The obtained results have shown that these characteristics are largely affected by illumination. The incorporation of dye molecules in porous silicon matrix enhanced photovoltaic properties of resulting structures.

2013-01-01T23:59:59.000Z

364

4, 58315854, 2004 Fluorescing aerosol  

E-Print Network [OSTI]

released by combustion into the atmosphere absorbs radiation and therefore heats the climate counteracting such as polycyclic aromatic hydrocarbons sticking to the aerosol particles, or bioaerosol such as bacteria, spores) or by combustion processes (soot), or they form in situ by gas to particle conversion, like sulphate aerosol. While

Paris-Sud XI, Université de

365

Effect of radio-frequency bias voltage on the optical and structural properties of hydrogenated amorphous silicon carbide  

SciTech Connect (OSTI)

Hydrogenated amorphous silicon carbide (a-Si{sub 1{minus}x}C{sub x}:H) films have been deposited using the electron cyclotron resonance chemical vapor deposition process under varying negative rf-bias voltage at the substrate. The optical and structural properties of these films are characterized using Rutherford backscattering spectroscopy, transmittance/reflectance spectrophotometry, photothermal deflection spectroscopy, Fourier transform infrared absorption, Raman scattering, and room temperature photoluminescence (PL). These films deposited using a gas mixture of silane, methane, and hydrogen at a constant gas flow ratio showed a slight increase in the carbon fraction x, but very obvious structural transformation, at increasing rf induced bias voltage from {minus}20 to {minus}120 V. Near stoichiometric a-Si{sub 1{minus}x}C{sub x}:H films with a carbon fraction x of almost 0.5 are achieved at low bias voltage range from {minus}20 to {minus}60 V. Visible PL with relatively low efficiency can be observed from such films at room temperature. For larger bias voltages from {minus}80 to {minus}120 V, slightly C-rich a-Si{sub 1{minus}x}C{sub x}:H films (x{gt}0.5) with larger optical gaps are obtained. These films have relatively higher PL efficiency, and the relative quantum efficiency was also found to depend strongly on the optical gap. Structurally, it was found that there is an increase in the hydrogen content and carbon sp{sup 2} bonding in the films at larger bias voltages. The latter leads to an increase in the disorder in the films. The linear relationship observed between the Urbach energy E{sub 0} and B factor in the Tauc equation suggests that the local defects related to microstructural disorder resulting from alloying with carbon dominate the overall defect structure of the films. Substrate biasing is noted to be crucial for the formation of Si{endash}C bonds, as deduced from the Raman scattering results. {copyright} 2001 American Institute of Physics.

Cui, J.; Rusli; Yoon, S. F.; Teo, E. J.; Yu, M. B.; Chew, K.; Ahn, J.; Zhang, Q.; Osipowicz, T.; Watt, F.

2001-06-01T23:59:59.000Z

366

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

SciTech Connect (OSTI)

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.

NONE

1997-02-01T23:59:59.000Z

367

Exciton–phonon complexes and optical properties in CdSe nanocrystals  

Science Journals Connector (OSTI)

A method to calculate the quantum states of exciton–phonon complexes in semiconductor nanocrystals is presented. The exciton–phonon complexes are built from a basis set made of products of phonon states and electron–hole pairs, which are coupled through the electron–phonon Fröhlich interaction, and the electron–hole Coulomb and exchange interactions. In CdSe nanocrystals, the conduction band electrons are described by the effective mass equation, while the holes are represented by the spherical 4 ? 4 Baldereschi–Lipari Hamiltonian. It is shown that a flexible and complete electron–hole basis, not limited to the 1s–1S3/2 octet, is essential to obtain converged eigenvalues and the correct polaron shift to the exciton energy. A study of the spectral properties is presented; in particular, the spectral region which involves the lowest exciton–phonon complex eigenstates is analysed in details. Specifically, the non-adiabatic nature of the exciton–phonon dynamics in the nanocrystals examined is clearly shown by the vibron eigenstates that were obtained.

E Menéndez-Proupin; N G Cabo-Bizet; C Trallero-Giner

2006-01-01T23:59:59.000Z

368

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

SciTech Connect (OSTI)

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 l’Éclairage 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.

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)

2013-03-15T23:59:59.000Z

369

Aerosol Laboratory - Nuclear Engineering Division (Argonne)  

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

Capabilities > Engineering Capabilities > Engineering Experimentation > Aerosol Laboratory Capabilities Engineering Experimentation Reactor Safety Experimentation Aerosol Experiments System Components Laser Applications Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Aerosol Laboratory The Aerosol Laboratory (AL) houses equipment to measure and record the physical parameters necessary to characterize the formation and transport of aerosols. Bookmark and Share The Aerosol Laboratory (AL) has extensive analytic and experimental capabilities to characterize the formation and transport of aerosols formed from the condensation of vapors. Computer codes have been developed to

370

Validation of Surface Retrieved Cloud Optical Properties with in situ Measurements at the Atmospheric Radiation Measurement Program (ARM) South Great Plains Site  

SciTech Connect (OSTI)

The surface inferred cloud optical properties from a multifilter rotating shadowband radiometer have been validated against the in situ measurements during the second ARM Enhanced Shortwave Experiment (ARESE II) field campaign at the ARM South Great Plains (SGP) site. On the basis of eight effective radius profiles measured by the in situ Forward Spectra Scattering Probe (FSSP), our retrieved cloud effective radii for single-layer warm water clouds agree well with in situ measurements, within 5.5%. The sensitivity study also illustrates that for this case a 13% uncertainty in observed liquid water path (LWP, 20 g/m2) results in 1.5% difference in retrieved cloud optical depth and 12.7% difference in referred cloud effective radius, on average. The uncertainty of the LWP measured by the microwave radiometer (MWR) is the major contributor to the uncertainty of retrieved cloud effective radius. Further, we conclude that the uncertainty of our inferred cloud optical properties is better than 5% for warm water clouds based on a surface closure study, in which cloud optical properties inferred from narrowband irradiances are applied to a shortwave model and the modeled broadband fluxes are compared to a surface pyranometer.

Min, Qilong; Duan, M.; Marchand, Roger T.

2003-09-11T23:59:59.000Z

371

ARM Aerosol Working Group Meeting  

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

and MFRSR Measurements ARM STM 2008 Norfolk, VA Connor Flynn 1 , Annette Koontz 1 , Anne Jefferson 2 , Jim Barnard 1 , Sally McFarlane 1 1 Pacific Northwest National Laboratory 2 CIRES, University of Colorado, Boulder Progress towards ARM DOE 2008 Performance Metric 3 & 4 * Produce and make available new continuous time series of aerosol total column depth, based on results from the AMF deployment in Niger, Africa. * Produce and make available new continuous time series of retrieved dust properties, based on results from the AMF deployment in Niger, Africa. 0 100 200 300 400 0 20 40 60 80 100 ITF movement and surface RH % RH day of year (2006) 0 100 200 300 400 0 50 100 150 200 250 300 350 day of year wind direction (N = 0, E = 90) 2 4 6 8 10 12 14 Wind speed m/s 0 100 200 300 1.4 1.6 1.8 2 MFRSR Vo for filter2, Niamey

372

Surface based remote sensing of aerosol-cloud interactions  

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

Surface based remote sensing of aerosol-cloud interactions Surface based remote sensing of aerosol-cloud interactions Feingold, Graham NOAA/Environmental Technology Laboratory Frisch, Shelby NOAA/Environmental Technology Laboratory Min, Qilong State University of New York at Albany Category: Cloud Properties We will present an analysis of the effect of aerosol on clouds at the Southern Great Plains ARM site. New methods for retrieving cloud droplet effective radius with radar (MMCR), multifilter rotating shadowband radiometer (MFRSR), and microwave radiometer (MWR) will be discussed. Relationships based on adiabatic clouds will be used to constrain retrievals. We will investigate the use of a range of proxies for cloud condensation nuclei, ranging from surface measurements of light scattering and accumulation mode number concentration, to lidar-measured extinction or

373

Optical and magneto-optical properties of Co-doped CeO{sub 2??} films in the 0.5 to 4?eV range  

SciTech Connect (OSTI)

Magnetically doped Ce{sub 1?x}Co{sub x}O{sub 2??} (nominal x?=?0.05 and 0.10) films were systematically studied by spectroscopic ellipsometry and magneto-optical spectroscopy. The samples were prepared by pulsed laser deposition on MgO(100) substrates and grew as textured polycrystalline films with thickness between 200 and 750?nm. They exhibited room temperature ferromagnetism and an out-of-plane easy axis attributed to magnetoelastic effects from the in-plane compressive strain. The dispersion of dielectric function of Ce{sub 1?x}Co{sub x}O{sub 2??} films was parametrized by the sum of Tauc-Lorentz and damped Lorentz oscillators and adjusted numerically. Deduced optical band gaps were similar to those of pure CeO{sub 2}, but the Co doping increased the optical absorption. The magneto-optical spectroscopy was carried out in both Faraday and Kerr configurations in the photon energy range from 0.5 to 4?eV, showing a strong dependence of the magneto-optical effect on the Co content near the optical band edge.

Veis, M., E-mail: veis@karlov.mff.cuni.cz; Kucera, M.; Zahradnik, M.; Antos, R. [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 12116 Prague (Czech Republic); Mistrik, J. [Faculty of Chemical Technology, University of Pardubice, 53210 Pardubice (Czech Republic); Bi, Lei; Kim, Hyun-Suk; Dionne, G. F.; Ross, C. A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-05-07T23:59:59.000Z

374

Structural and optical properties of InGaN–GaN nanowire heterostructures grown by molecular beam epitaxy  

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

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.

Limbach, F. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Gotschke, T. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Stoica, T. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Calarco, R. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany); Sutter, E. [Brookhaven National Lab., Upton, NY (United States); Ciston, J. [Brookhaven National Lab., Upton, NY (United States); Cusco, R. [Consell Superior d'Investigacions Cientifiques (CSIC), Barcelona (Spain); Artus, L. [Consell Superior d'Investigacions Cientifiques (CSIC), Barcelona (Spain); Kremling, S. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Hofling, S. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Worschech, L. [Univ. Wurzburg, Wilhelm Conrad Rontgen Research Centre Complex Matter Systems, Wurzburg (Germany); Grutzmacher, D. [Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany)

2011-01-07T23:59:59.000Z

375

Effects of defect clustering on optical properties of GaN by single and molecular ion irradiation  

SciTech Connect (OSTI)

The effects of irradiation by F, P, and PF{sub 4} on optical properties of GaN were studied experimentally and by atomistic simulations. Additionally, the effect of Ag was studied by simulation. The irradiation energy was 0.6?keV/amu for all projectiles. The measured photoluminescence (PL) decay time was found to be decreasing faster when irradiation was done by molecular ion compared to light ion irradiation. The PL decay time change is connected with the types of defect produced by different projectiles. Simulation results show that the light ions mainly produce isolated point defects while molecular and heavy ions produce clusters of point defects. The total amount of defects produced by the PF{sub 4} projectile was found to be very close to the sum of all defects produced in five individual cascades started by one P and four F single ions. This and the similar depth profiles of damage produced by molecular and light ion irradiations suggest that the defect clusters are one of the important reasons for fast PL decay. Moreover, the simulations of irradiation by Ag ions, whose mass is close to the mass of the PF{sub 4} molecule, showed that the produced defects are clustering in even bigger conglomerates compared to PF{sub 4} case. The latter has a tendency to split in the pre-surface region, reducing on average the density of the collision cascade.

Ullah, M. W., E-mail: mohammad.ullah@helsinki.fi; Kuronen, A.; Nordlund, K.; Djurabekova, F. [Department of Physics, University of Helsinki, P.O. Box 64, FIN 00014 (Finland); Karaseov, P. A.; Karabeshkin, K. V.; Titov, A. I. [Department of Physical Electronics, St. Petersburg State Polytechnic University, St. Petersburg (Russian Federation)

2013-11-14T23:59:59.000Z

376

Microstructural and nonlinear optical properties of silica–titania sol-gel film doped with PbS quantum dots  

Science Journals Connector (OSTI)

Thin silica–titania filmsdoped with different concentration of PbSquantum dots (PbS/oxide molar ratios ranging from 5% to 25%) were fabricated via a sol-gel route. The structuralproperties were studied by x-ray diffraction high-resolution transmission electron microscopy and Rutherford backscattering spectrometry. The PbS crystals were found to have a mean diameter in the range 2.3–3.5 nm with narrow size distribution. The resonant nonlinear optical properties were studied by the nonlinear m-line technique and degenerate four-wave mixing. High negative nonlinear refractive indices (n 2 ) were measured at 1.064 ?m. Different n 2 values were obtained for nanosecond excitation (n 2 =10 ?7 –10 ?8 ? cm 2 /kW ) and for picosecond excitation (n 2 =10 ?9 –10 ?10 ? cm 2 /kW ). The differences can be explained by saturation effects. Measurements at 532 nm showed n 2 values ten times higher than at 1.064 ?m. The response time of the nonlinearity for both wavelengths was below 35 ps.

A. Martucci; J. Fick; J. Schell; G. Battaglin; M. Guglielmi

1999-01-01T23:59:59.000Z

377

Secondary Aerosol: Precursors and Formation Mechanisms. Technical Report on Grant  

SciTech Connect (OSTI)

This project focused on studying trace gases that participate in chemical reactions that form atmospheric aerosols. Ammonium sulfate is a major constituent of these tiny particles, and one important pathway to sulfate formation is oxidation of dissolved sulfur dioxide by hydrogen peroxide in cloud, fog and rainwater. Sulfate aerosols influence the number and size of cloud droplets, and since these factors determine cloud radiative properties, sulfate aerosols also influence climate. Peroxide measurements, in conjunction with those of other gaseous species, can used to distinguish the contribution of in-cloud reaction to new sulfate aerosol formation from gas-phase nucleation reactions. This will lead to more reliable global climate models. We constructed and tested a new 4-channel fluorescence detector for airborne detection of peroxides. We integrated the instrument on the G-1 in January, 2006 and took a test flight in anticipation of the MAX-Mex field program, where we planned to fly under pressurized conditions for the first time. We participated in the 2006 Megacity Initiative: Local and Global Research Observations (MILAGRO) - Megacity Aerosol EXperiment â?? Mexico City (MAX-Mex) field measurement campaign. Peroxide instrumentation was deployed on the DOE G-1 research aircraft based in Veracruz, and at the surface site at Tecamac University.

Weinstein-Lloyd, Judith B

2009-05-04T23:59:59.000Z

378

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)

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 exchange–correlation 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.

Arghavani Nia, Borhan, E-mail: b.arghavani@gmail.com [Department of Physics, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Sedighi, Matin [Department of Physics, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Shahrokhi, Masoud [Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Moradian, Rostam [Nano-Science and Nano-Technology Research Center, Razi University, Kermanshah (Iran, Islamic Republic of); Computational Physics Science Research Laboratory, Department of Nano-Science, Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-1795, Tehran (Iran, Islamic Republic of)

2013-11-15T23:59:59.000Z

379

Airborne measurements of carbonaceous aerosols in southern Africa during  

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

Airborne measurements of carbonaceous aerosols in southern Africa during Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season Title Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season Publication Type Journal Article LBNL Report Number LBNL-50880 Year of Publication 2003 Authors Kirchstetter, Thomas W., Tihomir Novakov, and Peter V. Hobbs Journal Journal of Geophysical Research - Atmospheres Keywords black carbon, evolved gas analysis, light absorption, organic carbon, positive sampling artifact, SAFARI Abstract Particulate matter collected aboard the University of Washington's Convair-580 research aircraft over southern Africa during the dry, biomass burning season was analyzed for total carbon, organic carbon, and black carbon contents using thermal and optical methods. Samples were collected in smoke plumes of burning savanna and in regional haze. A known artifact, produced by the adsorption of organic gases on the quartz filter substrates used to collect the particulate matter samples, comprised a significant portion of the total carbon collected. Consequently, conclusions derived from the data are greatly dependent on whether or not organic carbon concentrations are corrected for this artifact. For example, the estimated aerosol co-albedo (1 - single scattering albedo), which is a measure of aerosol absorption, of the biomass smoke samples is 60% larger using corrected organic carbon concentrations. Thus, the corrected data imply that the biomass smoke is 60% more absorbing than do the uncorrected data. The black carbon to (corrected) organic carbon mass ratio (BC/OC) of smoke plume samples (0.18±0.06) is lower than that of samples collected in the regional haze (0.25±0.08). The difference may be due to mixing of biomass smoke with background air characterized by a higher BC/OC ratio. A simple source apportionment indicates that biomass smoke contributes about three-quarters of the aerosol burden in the regional haze, while other sources (e.g., fossil fuel burning) contribute the remainder.

380

Evidence that the spectral dependence of light absorption by aerosols is  

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

Evidence that the spectral dependence of light absorption by aerosols is Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon Title Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon Publication Type Journal Article LBNL Report Number LBNL-55056 Year of Publication 2004 Authors Kirchstetter, Thomas W., Tihomir Novakov, and Peter V. Hobbs Journal Journal of Geophysical Research: Atmospheres Volume 109 Issue D21 Keywords aerosol light absorption, biomass burning, organic carbon Abstract The wavelength dependence of light absorption by aerosols collected on filters is investigated throughout the near-ultraviolet to near-infrared spectral region. Measurements were made using an optical transmission method. Aerosols produced by biomass combustion, including wood and savanna burning, and by motor vehicles, including diesel trucks, are included in the analysis. These aerosol types were distinguished by different wavelength (λ) dependences in light absorption. Light absorption by the motor vehicle aerosols exhibited relatively weak wavelength dependence; absorption varied approximately as λ-1, indicating that black carbon (BC) was the dominant absorbing aerosol component. By contrast, the biomass smoke aerosols had much stronger wavelength dependence, approximately λ-2. The stronger spectral dependence was the result of enhanced light absorption at wavelengths shorter than 600 nm and was largely reduced when much of the sample organic carbon (OC) was extracted by dissolution in acetone. This indicates that OC in addition to BC in the biomass smoke aerosols contributed significantly to measured light absorption in the ultraviolet and visible spectral regions and that OC in biomass burning aerosols may appreciably absorb solar radiation. Estimated absorption efficiencies and imaginary refractive indices are presented for the OC extracted from biomass burning samples and the BC in motor vehicle-dominated aerosol samples. The uncertainty of these constants is discussed. Overall, results of this investigation show that low-temperature, incomplete combustion processes, including biomass burning, can produce light-absorbing aerosols that exhibit much stronger spectral dependence than high-temperature combustion processes, such as diesel combustion.

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

X-ray Spectral Survey of WGACAT Quasars, II: Optical and Radio Properties of Quasars with Low Energy X-ray Cut-offs  

E-Print Network [OSTI]

We have selected quasars with X-ray colors suggestive of a low energy cut-off, from the ROSAT PSPC pointed archive. We examine the radio and optical properties of these 13 quasars. Five out of the seven quasars with good optical spectra show associated optical absorption lines, with two having high delta-v candidate systems. Two other cut-off quasars show reddening associated with the quasar. We conclude that absorption is highly likely to be the cause of the X-ray cut-offs, and that the absorbing material associated with the quasars, not intervening along the line-of-sight. The suggestion that Gigahertz Peaked Sources are associated with X-ray cut-offs remains unclear with this expanded sample.

Martin Elvis; Fabrizio Fiore; Paolo Giommi; Paolo Padovani

1997-08-05T23:59:59.000Z

382

On the variations of optical property and electronic structure in heavily Al-doped ZnO films during double-step growth process  

SciTech Connect (OSTI)

We have investigated the variations of optical property and electronic structure in heavily Al-doped ZnO (AZO) films during the growth process, which were formed by first creating Zn vacancies in O{sub 2}-rich atmosphere and second filling the vacancies with Zn atoms in Zn-vapor atmosphere. After the first step, the high-resistance AZO films have the same optical bandgap with nominally undoped ZnO, indicating that negligible variations in the fundamental bandgap happened to the AZO films although Al atom was incorporated into the ZnO lattice. After the second step, once free electrons were brought into the lattice by Zn-filling, the optical transition energy blueshifts due to the band-filling effect. X-ray absorption fine structure measurements suggest that Zn-filling process decreased the unoccupied states of the conduction band, but not raised the conduction band minimum.

Hu, Q. C.; Ding, K., E-mail: kding@fjirsm.ac.cn; Zhang, J. Y.; Yan, F. P.; Pan, D. M.; Huang, F., E-mail: fhuang@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chiou, J. W., E-mail: jwchiou@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

2014-01-13T23:59:59.000Z

383

ARM - Surface Aerosol Observing System  

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

FacilitiesSurface Aerosol Observing System FacilitiesSurface Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments 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 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 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 equipped to quantify the interaction between clouds and aerosol particles. A counter-flow virtual impactor (CVI) is used to selectively sample cloud drops. The CVI takes advantage of the

384

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

ScienceCinema (OSTI)

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.

None

2014-06-03T23:59:59.000Z

385

Er{sup 3+}-doped strontium lithium bismuth borate glasses for broadband 1.5 {mu}m emission - optical properties  

SciTech Connect (OSTI)

Strontium lithium bismuth borate glasses (SLBiB) doped with various concentrations of Er{sup 3+} were prepared using conventional melt quench technique and investigated their optical properties. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction and SEM analysis. Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra at room temperature. Judd-Ofelt (J-O) theory has been applied for the f.f transitions of Er{sup 3+} ions to evaluate J-O intensity parameters, {Omega}{lambda} ({lambda} = 2, 4 and 6). Using the J-O intensity parameters, radiative properties such as transition probabilities (A{sub R}), branching ratios ({beta}) and radiative lifetimes ({tau}) are estimated for certain transitions. From the emission spectra, peak emission-cross sections ({sigma}{sub p}) and products of stimulated emission cross-section and full width at half maximum ({sigma}{sub p} Multiplication-Sign FWHM) were calculated for the observed emission transition, {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2}.

Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C. [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India)

2013-02-05T23:59:59.000Z

386

About ÂŤEffectiveÂŽ 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 "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 this component into the extinction of solar radiation under cloudless sky conditions. Sometimes it is important to know not only the total value of the aerosol component of extinction, but also to have the possibility to estimate the "effective" height of

387

Parameterizations of Cloud Microphysics and Indirect Aerosol Effects  

SciTech Connect (OSTI)

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 (bin

Tao, Wei-Kuo [NASA/GSFC] [NASA/GSFC

2014-05-19T23:59:59.000Z

388

Direct and semi-direct aerosol effects of Southern African1 biomass burning aerosol2  

E-Print Network [OSTI]

1 Direct and semi-direct aerosol effects of Southern African1 biomass burning aerosol2 Naoko effects of biomass burning aerosols from Southern African fires9 during July-October are investigated region the overall TOA radiative effect from the23 biomass burning aerosols is almost zero due

Wood, Robert

389

Effects of structure distortion on optical phonon properties of crystalline beta-BaTeMo{sub 2}O{sub 9}—A novel nonlinear optical material: Infrared and Raman spectra as well as first-principles calculations  

SciTech Connect (OSTI)

The infrared dielectric property of monoclinic BaTeMo{sub 2}O{sub 9} single crystals is studied by polarized IR reflectance spectra from 20 to 1800?cm{sup ?1}. Based on the modified Lorentz model, the frequencies, strengths, and dampings of TO modes as well as the orientations of the dipole momenta are determined, agreeing well with Raman spectra and results from First-principles calculation. The observed modes are visually assigned to the specific atoms' motions in the primitive cell based on the theory calculations. A large shift of the internal modes of the anion groups relative to free anion co-ordination polyhedra is observed, which can be used to indicate the distortions of co-ordination polyhedra related to the nonlinear optical properties. Further, the experimental results of the strengths of the oscillators support the elimination and splitting of degenerate modes in free regular polyhedrons. These results offer a way to evaluate the nonlinear optical properties by use of traditional IR reflectivity spectra.

Zhou, S. T.; Huang, Y.; Qiu, W. Y.; Li, Y. L.; He, S. M.; Zhang, B., E-mail: bozhang@mail.sitp.ac.cn, E-mail: xschen@mail.sitp.ac.cn, E-mail: luwei@mail.sitp.ac.cn; Chen, X. S., E-mail: bozhang@mail.sitp.ac.cn, E-mail: xschen@mail.sitp.ac.cn, E-mail: luwei@mail.sitp.ac.cn; Lu, W., E-mail: bozhang@mail.sitp.ac.cn, E-mail: xschen@mail.sitp.ac.cn, E-mail: luwei@mail.sitp.ac.cn [National Lab for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu Tian Road, Shanghai 200083 (China); Zhang, J. J.; Tao, X. T. [State Key Laboratory of Crystal Materials, Shangdong University, 27 South Shanda Road, Jinan, Shangdong 250100 (China)

2013-12-21T23:59:59.000Z

390

Reflective Aerosols and the Greenhouse Effect  

Science Journals Connector (OSTI)

The contributions of atmospheric aerosols to add to either a climate-warming effect or climate-cooling effect depend on the chemical composition of the aerosol and the local environment. The best estimation is...

Kathryn E. Kautzman

2014-07-01T23:59:59.000Z

391

Antiviral therapy with small particle aerosols  

Science Journals Connector (OSTI)

The generation and use of small particle aqueous aerosols (1.23 µm aerodynamic mass median diameter, GSD=2.0 µm) containing ribavirin is described. Administered via aerosol, ribavirin will be deposited rather ...

V. Knight; B. Gilbert

1988-12-01T23:59:59.000Z

392

Design of a Shadowband Spectral Radiometer for the Retrieval of Thin Cloud Optical Depth, Liquid Water Path, and the Effective Radius  

SciTech Connect (OSTI)

The design and operation of a Thin-Cloud Rotating Shadowband Radiometer (TCRSR) described here was used to measure the radiative intensity of the solar aureole and enable the simultaneous retrieval of cloud optical depth, drop effective radius, and liquid water path. The instrument consists of photodiode sensors positioned beneath two narrow metal bands that occult the sun by moving alternately from horizon to horizon. Measurements from the narrowband 415-nm channel were used to demonstrate a retrieval of the cloud properties of interest. With the proven operation of the relatively inexpensive TCRSR instrument, its usefulness for retrieving aerosol properties under cloud-free skies and for ship-based observations is discussed.

Bartholomew M. J.; Reynolds, R. M.; Vogelmann, A. M.; Min, Q.; Edwards, R.; Smith, S.

2011-11-01T23:59:59.000Z

393

Active Spectral Nephelometry in Studies of the Condensational Activity of Submicron Aerosol  

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

Active Spectral Nephelometry in Studies of the Active Spectral Nephelometry in Studies of the Condensational Activity of Submicron Aerosol M. V. Panchenko, S. A. Terpugova, and V. S. Kozlov Institute of Atmospheric Optics Russian Academy of Sciences Tomsk, Russia M. A. Sviridenkov A. M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow, Russia A. S. Kozlov Institute of Chemical Kinetics and Combustion Russian Academy of Sciences Novosibirsk, Russia Introduction Water vapor condensation and evaporation are among the main processes of the atmospheric aerosol transformation essentially affecting its optical and radiative characteristics. Most of the known methods for investigating the aerosol condensation activity are based on measurements of only the changes in the

394

Property  

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

7 7 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: INFORMATION: Audit Report on "Personal Property at the Oak Ridge Operations Office and the Office of Scientific and Technical Information" BACKGROUND The Oak Ridge Operations Office (Operations Office) and the Office of Scientific and Technical Information

395

Influence of film thickness, substrate temperature and nano-structural changes on the optical properties of UHV deposited Ti thin films  

Science Journals Connector (OSTI)

Titanium films of different thicknesses ranging from 18 to 210?nm were deposited on glass substrates, at different substrate temperatures (313 to 600?K) under UHV conditions. Their optical properties were measured by spectrophotometry in the spectral range of 200–2500?nm. The optical functions were obtained from the Kramers–Kronig analysis of the reflectivity curves. The effective medium approximation (EMA) analysis was employed to establish the relationship between the structure zone model (SZM) and EMA predictions. There was good agreement between SZM as a function of substrate temperature and film thickness and the values of volume fraction of voids was obtained from EMA analysis. The gettering property of Ti can play an important role in the nano-structure of the film and causes variations in the optical behaviour of thin Ti films, though films were produced under UHV condition and the XRD analysis did not show a detectable amount of oxidation. The over-layer thickness was calculated to be less than 2.0?nm, using the transfer matrix method.

Hadi Savaloni; Haleh Kangarloo

2007-01-01T23:59:59.000Z

396

2, 20952131, 2002 Below-cloud aerosol  

E-Print Network [OSTI]

). In addition, the understanding of wet removal processes remains crucial in local and regional pollutionACPD 2, 2095­2131, 2002 Below-cloud aerosol removal C. Andronache Title Page Abstract Introduction-cloud aerosol removal by rainfall for observed aerosol size distributions C. Andronache Boston College, Chestnut

Paris-Sud XI, Université de

397

6, 93519388, 2006 Aerosol-cloud  

E-Print Network [OSTI]

ACPD 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al Chemistry and Physics Discussions Aerosol-cloud interaction inferred from MODIS satellite data and global 6, 9351­9388, 2006 Aerosol-cloud interaction inferred from MODIS and models G. Myhre et al. Title

Paris-Sud XI, Université de

398

Optical properties of Ag nanoparticle-polymer composite film based on two-dimensional Au nanoparticle array film  

Science Journals Connector (OSTI)

The nanocomposite polyvinyl pyrrolidone (PVP) films containing Ag nanoparticles and Rhodamine 6G are prepared on the two-dimensional distinctive continuous ultrathin gold nanofilms. We investigate the optical pro...

Long-De Wang; Tong Zhang; Xiao-Yang Zhang; Yuan-Jun Song…

2014-03-01T23:59:59.000Z

399

ARM - Measurement - Aerosol backscattered radiation  

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

backscattered radiation backscattered radiation 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 backscattered radiation The scattering of radiant energy into the hemisphere of space bounded by a plane normal to the direction of the incident radiation and lying on the same side as the incident ray. 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 recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System MPL : Micropulse Lidar NEPHELOMETER : Nephelometer

400

The Optical Properties of Cu-Ni Nanoparticles Produced via Pulsed Laser Dewetting of Ultrathin Films: The Effect of Nanoparticle Size and Composition on the Plasmon Response  

SciTech Connect (OSTI)

Thin film Cu-Ni alloys ranging from 2-8nm were synthesized and their optical properties were measured as-deposited and after a laser treatment which dewet the films into arrays of spatially correlated nanoparticles. The resultant nanoparticle size and spacing are attributed to laser induced spinodal dewetting process. The evolution of the spinodal dewetting process is investigated as a function of the thin film composition which ultimately dictates the size distribution and spacing of the nanoparticles. The optical measurements of the copper rich alloy nanoparticles reveal a signature absorption peak suggestive of a plasmonic peak which red-shifts with increasing nanoparticle size and blue shifts and dampens with increasing nickel concentration.

Wu, Yeuyeng [University of Tennessee, Knoxville (UTK); Fowlkes, Jason Davidson [ORNL; Rack, Philip D [ORNL

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "aerosol optical properties" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

AEROSOL DIRECT RADIATIVE EFFECTS OVER THE NORTHWEST ATLANTIC, NORTHWEST PACIFIC, AND NORTH INDIAN OCEANS  

E-Print Network [OSTI]

AEROSOL DIRECT RADIATIVE EFFECTS OVER THE NORTHWEST ATLANTIC, NORTHWEST PACIFIC, AND NORTH INDIAN, NORTHWEST PACIFIC, AND NORTH INDIAN OCEANS: ESTIMATES BASED ON IN-SITU CHEMICAL AND OPTICAL MEASUREMENTS, Y.24 , Tang, Y.25 , Weber, R. J.26 , and Wu, Y.27 1 NOAA/PMEL, 7600 Sand Point Way NE, Seattle, WA

402

Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere  

E-Print Network [OSTI]

of cirrus clouds is demonstrated and explained theoretically, which provides guidance in the calibra¬tion algorithm for 1.064-µm channel on the Calipso lidar. Dust aerosols have no particular morphology. To develop an approach to modeling the optical...

Bi, Lei

2012-07-16T23:59:59.000Z

403

An Assessment of the Impact of Antishattering Tips and Artifact Removal Techniques on Bulk Cloud Ice Microphysical and Optical Properties Measured by the 2D Cloud Probe  

Science Journals Connector (OSTI)

A recent study showed that the ratio of the number of distribution functions derived from 2D cloud probes (2DCs) with standard tips to those with antishatter tips used during the 2008 Indirect and Semidirect Aerosol Campaign (ISDAC) and ...

Robert C. Jackson; Greg M. McFarquhar

2014-10-01T23:59:59.000Z

404

Effect of Mg doping on the growth aspects, crystalline perfection, and optical and thermal properties of congruent LiNbO3 single crystals  

Science Journals Connector (OSTI)

Single crystals of Mg-doped lithium niobate with diffrent dopant concentrations were grown using a automatic diameter controlled crystal puller. Crack formation at the higher dopant concentration (6 mol%) was observed, although a good-quality crystal could be grown at the same concentration with a change in the pulling rate; this result is related to the thermal conductivity of the material. An investigation of the crystalline perfection and optical properties and a thermal analysis were carried out, in consideration of potential usage for device fabrication.

Riscob, B.

2013-10-26T23:59:59.000Z

405

Effect of deposition temperature on the structural and optical properties of CdSe thin films synthesised by chemical bath deposition  

SciTech Connect (OSTI)

Cadmium selenide thin films were synthesized on glass substrates using chemical bath technique (CBD) at temperatures 320K, 330K, 340K,and 350K. The polycrystalline nature of the material was confirmed by X-ray diffraction technique and various structural parameters such as lattice parameters, grain size, dislocation density, and micro strain. The root mean square (RMS) roughness was obtained by using atomic force microscopy(AFM), which indicated a decreasing average roughness with the decrease of the bath temperature. Optical properties were carried out by UV-Visible transmittance spectra, and the band gap energy was determined.

Mohammed, Mudhafer Ali [Department of Applied Sciences, University of Technology / Baghdad (Iraq); Jamil, Shatha Shammon Batros [Ministry of Science and Technology / Baghdad (Iraq)

2013-12-16T23:59:59.000Z

406

Submicrosized Rods, Cables, and Tubes of ZnE (E = S, Se, Te): Exterior?Interior Boron-Chalcogen Conversions and Optical Properties  

Science Journals Connector (OSTI)

Submicrosized Rods, Cables, and Tubes of ZnE (E = S, Se, Te): Exterior?Interior Boron-Chalcogen Conversions and Optical Properties ... The absence of ZnO judging from the XRD (part d of Figure 3) and the disappearance of the core as shown in the SEM images (parts c and d of Figure 5) allow us to conclude that the intermediate product is heterostructure with ZnO as core and ZnS as sheath, that is, the ZnO/ZnS cable. ...

Yi-Zhi Huang; Ling Chen; Li-Ming Wu

2008-10-15T23:59:59.000Z

407

Review of models applicable to accident aerosols  

SciTech Connect (OSTI)

Estimations of potential airborne-particle releases are essential in safety assessments of nuclear-fuel facilities. This report is a review of aerosol behavior models that have potential applications for predicting aerosol characteristics in compartments containing accident-generated aerosol sources. Such characterization of the accident-generated aerosols is a necessary step toward estimating their eventual release in any accident scenario. Existing aerosol models can predict the size distribution, concentration, and composition of aerosols as they are acted on by ventilation, diffusion, gravity, coagulation, and other phenomena. Models developed in the fields of fluid mechanics, indoor air pollution, and nuclear-reactor accidents are reviewed with this nuclear fuel facility application in mind. The various capabilities of modeling aerosol behavior are tabulated and discussed, and recommendations are made for applying the models to problems of differing complexity.

Glissmeyer, J.A.

1983-07-01T23:59:59.000Z

408

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 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 Satellite Cloud Climatology Project (ISCCP) (Rossow and Schiffer 1991; Rossow and Schiffer 1999). However, there is a dearth of information concerning the global climatology of cloud vertical structure and cirrus cloud properties. This is because the often-used

409

Determination of the Optical Properties of La2 xBaxCuO4 for Several Dopings, Including the Anomalous x = 1/8 Phase  

SciTech Connect (OSTI)

The optical properties of single crystals of the high-temperature superconductor La{sub 2-x}Ba{sub x}CuO{sub 4} 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 T{sub c} = 32 K, x = 0.125 where the superconductivity is dramatically weakened with T{sub c} {approx_equal} 2.4 K, and x = 0.145 with T{sub c} {approx_equal} 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 T{sub c} in the x = 0.095 and 0.145 materials there is a clear signature of the formation of a superconducting state in the optical properties allowing the superfluid density ({rho}{sub s0}) and the penetration depth to be determined. In the anomalous 1/8 phase, some spectral weight shifts from lower to higher frequency ({ge} 300 cm{sup -1}) on cooling below the spin-ordering temperature T{sub so} {approx_equal} 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 {rho}{sub s0}/8 {approx_equal} 4.4 {sigma}{sub dc}T{sub c}, 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 T{sub c}.

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

2012-04-11T23:59:59.000Z

410

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

SciTech Connect (OSTI)

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.

Das, Sayantan; Alford, T. L. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA and School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA and School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)

2013-06-28T23:59:59.000Z

411

Formation and optical properties of CdTe/ZnTe nanostructures with different CdTe thicknesses grown on Si (100) substrates  

SciTech Connect (OSTI)

Atomic force microscopy (AFM) and photoluminescence (PL) measurements were carried out to investigate the formation and the optical properties of CdTe/ZnTe nanostructures with various CdTe thicknesses grown on Si (100) substrates by using molecular beam epitaxy and atomic layer epitaxy. AFM images showed that uniform CdTe/ZnTe quantum dots with a CdTe layer thickness of 2.5 ML (monolayer) were formed on Si (100) substrates. The excitonic peaks corresponding to transitions from the ground electronic subband to the ground heavy-hole band in the CdTe/ZnTe nanostructures shifted to a lower energy with increasing thickness of the CdTe layer. The activation energies of the carriers confined in the CdTe/ZnTe nanostructures grown on Si (100) substrates were obtained from the temperature-dependent PL spectra. The present observations can help improve understanding of the formation and the optical properties in CdTe/ZnTe nanostructures with different CdTe thicknesses grown on Si (100) substrates.

Lee, H. S.; Park, H. L.; Lee, I.; Kim, T. W. [Department of Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Advanced Semiconductor Research Center, Division of Electronics and Computer Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

2007-11-15T23:59:59.000Z

412

Aerosol indirect effects -- general circulation model intercomparison and evaluation with satellite data  

SciTech Connect (OSTI)

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.

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

2009-04-10T23:59:59.000Z

413

Examination of the Effects of Sea Salt Aerosols on Southeast Texas Ozone and Secondary Organic Aerosol  

E-Print Network [OSTI]

of this research is to examine sea salt aerosols and their impact on polluted environments. Sea salt aerosols act as Cloud Condensation Nuclei (CCN) as well as providing a surface for heterogeneous reactions. Such reactions have implications for trace gases...

Benoit, Mark David

2013-02-06T23:59:59.000Z

414

Role of surface states and defects in the ultrafast nonlinear optical properties of CuS quantum dots  

SciTech Connect (OSTI)

We report facile preparation of water dispersible CuS quantum dots (2–4 nm) and nanoparticles (5–11 nm) through a nontoxic, green, one-pot synthesis method. Optical and microstructural studies indicate the presence of surface states and defects (dislocations, stacking faults, and twins) in the quantum dots. The smaller crystallite size and quantum dot formation have significant effects on the high energy excitonic and low energy plasmonic absorption bands. Effective two-photon absorption coefficients measured using 100 fs laser pulses employing open-aperture Z-scan in the plasmonic region of 800 nm reveal that CuS quantum dots are better ultrafast optical limiters compared to CuS nanoparticles.

Mary, K. A. Ann; Unnikrishnan, N. V., E-mail: nvu100@yahoo.com [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Philip, Reji [Light and Matter Physics Group, Raman Research Institute, C.V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)

2014-07-01T23:59:59.000Z

415

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) govCampaignsTwo-Column Aerosol Project (TCAP) Campaign Links TCAP website 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 2012.07.15, Dubey, AMF Two-Column Aerosol Project (TCAP): Aerial Campaign 2012.07.07, Berg, AAF Two-Column Aerosol Project (TCAP): Aerodynamic Particle Sizer 2012.07.01, Berg, AMF Two-Column Aerosol Project (TCAP): KASPRR Engineering Tests 2012.07.01, Mead, AMF Two-Column Aerosol Project (TCAP): Airborne HSRL and RSP Measurements

416

Direct and semidirect aerosol effects of southern African biomass burning aerosol  

E-Print Network [OSTI]

Direct and semidirect aerosol effects of southern African biomass burning aerosol Naoko Sakaeda,1 2011; published 21 June 2011. [1] Direct and semidirect radiative effects of biomass burning aerosols static stability. Over the entire region the overall TOA radiative effect from the biomass burning

Wood, Robert

417

Carbonaceous Aerosol Study Using Advanced Particle Instrumentation  

E-Print Network [OSTI]

particles from the combustion of biomass fuels. Environ.range transport of biomass combustion aerosols. Environ.during the open combustion of biomass in the laboratory, J.

Qi, Li

2010-01-01T23:59:59.000Z

418

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)

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.

Sayede, A. [Universite Lille Nord de France, F-59000 Lille (France); Khenata, R. [Laboratoire de Physique Quantique et de Modlisation Mathmatique, Universite de Mascara, Mascara, 29000 (Algeria); Chahed, A.; Benhelal, O. [Condensed Matter and Sustainable Development Laboratory, Djillali Liabes University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria)

2013-05-07T23:59:59.000Z

419

Comparative Analysis of Urban Atmospheric Aerosol by Particle...  

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

Analysis of Urban Atmospheric Aerosol by Particle-Induced X-ray Emission (PIXE), Proton Elastic Scattering Analysis Comparative Analysis of Urban Atmospheric Aerosol by...

420

The Two-Column Aerosol Project Definitions TCAP Educational  

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

What's the big deal about aerosols? The Two-Column Aerosol Project Definitions TCAP Educational Outreach Activity About ARM: The Atmospheric Radiation Measurement (ARM) Climate...

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421

Reduction in biomass burning aerosol light absorption upon humidificat...  

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

in biomass burning aerosol light absorption upon humidification: Roles of inorganically-induced hygroscopicity, Reduction in biomass burning aerosol light absorption upon...

422

The Indirect and Semi-Direct Aerosol Campaign  

SciTech Connect (OSTI)

Research projects like the Indirect and Semi-Direct Aerosol Campaign, or ISDAC, increase our knowledge of atmospheric aerosol particles and cloud physics.

Ghan, Steve

2014-03-24T23:59:59.000Z

423

Molecular Chemistry of Organic Aerosols Through the Application...  

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

Chemistry of Organic Aerosols Through the Application of High Resolution Mass Spectrometry. Molecular Chemistry of Organic Aerosols Through the Application of High Resolution Mass...

424

Tailorable optical scattering properties of the V-shaped plasmonic nano-antennas: a computationally efficient and fast analysis  

E-Print Network [OSTI]

We introduce an efficient computational scheme based on Macro Basis Function (MBF) method, to analyze the scattering of a plane wave by the V-shaped plasmonic optical nano-antennas. The polarization currents and the scattered fields for symmetric and anti-symmetric excitations are investigated. We investigate how the resonant frequency of the plasmonic V-shaped nanoantenna is tailored by engineering the geometrical parameters and by changing the polarization state of the incident plane wave. The computational model presented herein is faster by orders of magnitude than commercially available finite methods and is capable to characterize also other nanoantennas comprising of junctions and bends of nanorods.

Rashidi, Arash; Anagnostou, Dimitris E

2015-01-01T23:59:59.000Z

425

Structural and optical properties of GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells  

SciTech Connect (OSTI)

GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells are grown by laser-assisted sputtering. Structural and optical studies of the heterostructures are carried out. A broad photoluminescence line is observed in the wavelength range from 1300 to 1650 nm. The line corresponds to indirect transitions in the momentum space of the Ge quantum wells and to transitions between the In{sub 0.28}Ga{sub 0.72}As and Ge layers, indirect in coordinate space, but direct in momentum space.

Aleshkin, V. Ya.; Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Drozdov, M. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N. [Nizhni Novgorod State University, Research Physical Technical Institute (Russian Federation); Kudryavtsev, K. E.; Tonkikh, A. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

2013-05-15T23:59:59.000Z

426

Photometric Variations as Small Perturbations in Aerosol Content  

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

Photometric Variations as Photometric Variations as Small Perturbations in Aerosol Content I. Musat Department of Meteorology University of Maryland College Park, Maryland R. G. Ellingson Department of Meteorology Florida State University Tallahassee, Florida Abstract The quality of profile fitting of resolved stars depends ultimately upon the accuracy with which spectral differences of the sources are retrievable within the data, because the radiation color of well-separated known sources can serve as an indicator of the origin of the optical depth variations one observes during the night. The particularities of the whole sky imager (WSI) detector and optical system are such that the data suffer from lack of the spatial resolution required in a common astronomical observation.

427

Optical and carrier transport properties of graphene oxide based crystalline-Si/organic Schottky junction solar cells  

SciTech Connect (OSTI)

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 12–15?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 2–3?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.

Khatri, I.; Tang, Z.; Hiate, T.; Liu, Q.; Ishikawa, R.; Ueno, K.; Shirai, H. [Graduate School of Science and Engineering, Saitama University, Saitama 338-8570 (Japan)

2013-12-21T23:59:59.000Z

428

Optical properties of nanocrystalline WO{sub 3} and WO{sub 3-x} thin films prepared by DC magnetron sputtering  

SciTech Connect (OSTI)

The optical properties of tungsten trioxide thin films prepared by DC magnetron sputtering, with different oxygen vacancy (V{sub o}) concentration, have been studied by spectrophotometry and photoluminescence (PL) emission spectroscopy. Absorption and PL spectra show that the films exhibit similar band gap energies, E{sub g} ? 2.9?eV. The absorption spectra of the films show two pronounced absorption bands in the near-infrared region. One peak (P1) is located at approximately 0.7?eV, independent of V{sub o} concentration. A second peak (P2) shifts from 0.96?eV to 1.16?eV with decreasing V{sub o} concentration. Peak P1 is assigned to polaron absorption due to transitions between tungsten sites (W{sup 5+}???W{sup 6+}), or an optical transition from a neutral vacancy state to the conduction band, V{sub o}{sup 0}???W{sup 6+}. The origin of peak P2 is more uncertain but may involve +1 and +2 charged vacancy sites. The PL spectra show several emission bands in the range 2.07 to 3.10?eV in the more sub-stoichiometric and 2.40 to 3.02?eV in the less sub-stoichiometric films. The low energy emission bands agree well with calculated optical transition energies of oxygen vacancy sites, with dominant contribution from neutral and singly charged vacancies in the less sub-stoichiometric films, and additional contributions from doubly charged vacancy sites in the more sub-stoichiometric films.

Johansson, Malin B., E-mail: majo4400@gmail.com; Niklasson, Gunnar A.; Österlund, Lars, E-mail: lars.osterlund@angstrom.uu.se [Division of Solid State Physics, Department of Engineering Sciences, The Ĺngström Laboratory, Uppsala University, P.O. Box 534, SE-75121 Uppsala (Sweden); Zietz, Burkhard [Division of Physical Chemistry, Department of Chemistry, The Ĺngström Laboratory, Uppsala University, P.O. Box 523, SE-75120 Uppsala (Sweden)

2014-06-07T23:59:59.000Z

429

Optical and electrical properties study of sol-gel derived Cu{sub 2}ZnSnS{sub 4} thin films for solar cells  

SciTech Connect (OSTI)

The fabrication of environmental-friendly Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films with pure kesterite phase is always a challenge to researchers in the field of solar cells. We introduce a simple non-vacuum sol-gel method to fabricate kesterite CZTS films. Ethylenediamine is used as the chelating agent and stabilizer and plays an important role in preparing stable precursor. X-ray diffraction, Raman and scanning electron microscopy studies suggest that the microstructure and optical properties of CZTS films depend strongly on annealing temperatures. The temperature dependence of conductivity of 500?°C annealed CZTS film shows that the Mott law dominates in the low temperature region and thermionic emission is predominant at high temperatures.

Guo, B. L.; Liu, X. J.; Li, A. D., E-mail: wcliu@nju.edu.cn, E-mail: adli@nju.edu.cn [National Laboratory of Solid State Microstructures, College of Engineering and Applied Science, Nanjing University, Nanjing 210093 (China); Chen, Y. H. [National Laboratory of Solid State Microstructures, Photovoltaic Engineering Center, Nanjing University, Nanjing 210093 (China); Liu, W. C., E-mail: wcliu@nju.edu.cn, E-mail: adli@nju.edu.cn [National Laboratory of Solid State Microstructures, College of Engineering and Applied Science, Nanjing University, Nanjing 210093 (China); National Laboratory of Solid State Microstructures, Photovoltaic Engineering Center, Nanjing University, Nanjing 210093 (China)

2014-09-15T23:59:59.000Z

430

Optical properties of boron carbide near the boron K edge evaluated by soft-x-ray reflectometry from a Ru/B4C multilayer  

SciTech Connect (OSTI)

Soft-x-ray Bragg reflection from two Ru/B4C multilayers with 10 and 63 periods was used for independent determination of both real and imaginary parts of the refractive index n = 1 -{delta} + i{beta} close to the boron K edge ({approx}188 eV). Prior to soft x-ray measurements, the structural parameters of the multilayers were determined by x-ray reflectometry using hard x rays. For the 63-period sample, the optical properties based on the predictions made for elemental boron major deviations were found close to the K edge of boron for the 10-period sample explained by chemical bonding of boron to B4C and various boron oxides.

Ksenzov, Dmitriy; Panzner, Tobias; Schlemper, Christoph; Morawe, Christian; Pietsch, Ullrich

2009-12-10T23:59:59.000Z

431

DFT calculations study of structural, electronic, and optical properties of Cu2ZnSn(S1?xSex)4 alloys  

Science Journals Connector (OSTI)

Abstract As promising solar cell absorb materials, detailed density functional theory calculations of the structural, electronic, and optical properties of Cu2ZnSn(S1?xSex)4 alloys with different crystal structures (including: zincblende-derived kesterite, zincblende-derived stannite, wurtzite-derived kesterite, and wurtzite-derived stannite) over the whole range of Se composition from x = 0 to x = 1 were systematically investigated in the present work. The calculated results revealed that the lattice constants variation of Cu2ZnSn(S1?xSex)4 alloys obey the Vegard’s law; and the wurtzite-derived alloys have better alloy solubility and component-uniform compared with zincblende-derived alloys. In the whole range of x, the calculated lattice constants, band gaps, dielectric constants, and refractive index are nearly linear varying with Se compositions. Using the fitting functional relationships, one not only designs suitable Cu2ZnSn(S1?xSex)4 alloys as absorber materials for solar cells, but also determines the composition of Cu2ZnSn(S1?xSex)4 alloys by conventional optical measurements in practice.

Zong-Yan Zhao; Qing-Lu Liu; Xiang Zhao

2015-01-01T23:59:59.000Z

432

Electronic and optical properties of ScN and (Sc,Mn)N thin films deposited by reactive DC-magnetron sputtering  

SciTech Connect (OSTI)

Scandium nitride (ScN) is a rocksalt semiconductor that has attracted significant attention from various researchers for a diverse range of applications. Motivated by the prospect of using its interesting electronic structure for optoelectronic and dilute magnetic semiconductor applications, we present detailed studies of the electronic transport and optical properties of ScN and its alloys with manganese nitride (MnN). Our results suggest (a) dilute manganese doping in ScN compensates for the high n-type carrier concentrations arising due to oxygen impurities and (b) an n-type to p-type carrier type transition occurs at a composition between 5.8% and 11% Mn on Sc sites. In terms of its optical properties, our analysis clearly indicates direct and indirect bandgap absorption edges of ScN located at 2.04 eV and 1.18 eV, respectively. In addition to the direct gap absorption edge, (Sc,Mn)N samples also show Mn-defect induced electronic absorption. Photoluminescence measurements at room temperature from ScN films exhibit a yellowish-green emission corresponding to direct gap radiative recombination. Direct gap recombination is not expected given the smaller indirect gap. A possible role of high excitation intensities in suppressing relaxation and recombination across the indirect bandgap is suspected. Raman spectroscopic and ellipsometric characterization of the dielectric permittivities of ScN and (Sc,Mn)N are also presented to assist in understanding the potential of ScN for optoelectronic applications.

Saha, Bivas [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States) [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Naik, Gururaj; Boltasseva, Alexandra [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States) [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Drachev, Vladimir P. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States) [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics, University of North Texas, Denton, Texas 76203 (United States); Marinero, Ernesto E. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Sands, Timothy D. [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States) [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2013-08-14T23:59:59.000Z

433

Electro-optical properties of UV-emitting InGaN heterostructures considering injection-induced conductivity  

SciTech Connect (OSTI)

Some radiative and electric properties of heterostructures based on semiconductor nitrides emitting in the visible and UV regions are considered. The following anomalous properties of UV-emitting heterostructures are studied: the low-temperature emission quenching, a strong non-ideality of I-V curves, and the increase in the slope of these characteristics upon cooling. The anomalous emission quenching is especially typical for {approx}3-nm thick single-quantum-well structures, but it is absent in a 50-nm thick double heterostructure. It seems that this difference is caused by the fact that the capture of carriers at the levels in quantum wells slows down upon cooling, and a 'through' injection of carriers occurs into the opposite emitter layer. In addition, electrons injected into the p region reduce its resistance. The consideration of the injection-induced conductivity in the passive layer allows us to explain satisfactorily the electric anomalies. (active media)

Eliseev, P G [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Lee, J; Osinski, M A [Centre for High-Technology Materials, University of New Mexico, Albuquerque (United States)

2004-12-31T23:59:59.000Z

434

Investigation of Thin Cirrus Cloud Optical and Microphysical Properties on the Basis of Satellite Observations and Fast Radiative Transfer Models  

E-Print Network [OSTI]

function of ?CALIOP. the frequency is scaled by dividing the largest frequency in each ?CALIOP bin. Data are from collocated MODIS and CALIOP measurements made in August 2006. ............... 126 5.7 Daytime frequencies of (a) cloud, (b) ice cloud, (c...) and Stubenrauch et al. (2006) investigated the climatology of thin cirrus properties. 1.2.2 Limb-view-instrument-based observations Limb-view-instruments observe cloud or atmosphere by eliminating the signals from the surface and therefore increase the SNRs...

Wang, Chenxi

2013-07-25T23:59:59.000Z

435

Atmospheric aerosols versus greenhouse gases in the twenty-first century  

Science Journals Connector (OSTI)

...Say it is thus with what you show me. (Charles Dickens, A Christmas Carol, 1843) 1. Introduction The evolution of human society...properties of the aerosol. Sulphates, which do not absorb visible light, have been the dominant species responsible for the cooling...

2007-01-01T23:59:59.000Z

436

BNL | Mobile Aerosol Observing System (MAOS)  

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

Mobile Aerosol Observing System (MAOS) Mobile Aerosol Observing System (MAOS) The Mobile Aerosol Observing System (MAOS) is a platform and instrument suite for Intensive Operation Periods (IOPs) to conduct in situ measurements of aerosols and their precursors. MAOS is part of the ARM Climate Research Facility. Physically MAOS is contained in two 20' SeaTainers custom adapted to provide a sheltered laboratory environment for operators and instruments even under harsh conditions. The two structures are designated MAOS-A and MAOS-C for Aerosol and Chemistry respectively. Although independent, with separate data systems, inlets and power distribution, the two structures are normally a single operating unit. The two enclosures comprising MAOS are designed for rapid deployment. All components (except for the Radar Wind Profiler) are transported internally

437

The Opposed Migration Aerosol Classifier (OMAC)  

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

The Opposed Migration Aerosol Classifier (OMAC) The Opposed Migration Aerosol Classifier (OMAC) Speaker(s): Harmony Gates Date: February 22, 2007 - 12:00pm Location: 90-4133 Seminar Host/Point of Contact: Melissa Lunden A new differential mobility classifier will be described. The instrument classifies aerosol particles in a channel flow between porous (or screen) electrodes. The aerosol enters the channel parallel to the porous electrodes, while a larger, particle-free cross-flow enters through one of the porous electrode. A potential difference between electrodes causes the charged aerosol particles to migrate upstream against the cross-flow. Only particles whose upward migration velocity balances the cross flow will be transmitted along the path of the classifier. Simulations of the OMAC show that it should give the same resolution at the traditional

438

The Nature of Nearby Counterparts to Intermediate Redshift Luminous Compact Blue Galaxies I. Optical/H I Properties and Dynamical Masses  

E-Print Network [OSTI]

We present single-dish H I spectra obtained with the Green Bank Telescope, along with optical photometric properties from the Sloan Digital Sky Survey, of 20 nearby (D < 70 Mpc) Luminous Compact Blue Galaxies (LCBGs). These ~L*, blue, high surface brightness, starbursting galaxies were selected with the same criteria used to define LCBGs at higher redshifts. We find these galaxies are gas-rich, with M(HI) ranging from 5*10^8 to 8*10^9 M_sun, and M(HI)/L_B ranging from 0.2 to 2 M_sun/L_sun, consistent with a variety of morphological types of galaxies. We find the dynamical masses (measured within R_25) span a wide range, from 3*10^9 to 1*10^11 M_sun. However, at least half have dynamical mass-to-light ratios smaller than nearby galaxies of all Hubble types, as found for LCBGs at intermediate redshifts. By comparing line widths and effective radii with local galaxy populations, we find that LCBGs are consistent with the dynamical mass properties of Magellanic (low luminosity) spirals, and the more massive irregulars and dwarf ellipticals, such as NGC 205.

C. A. Garland; D. J. Pisano; J. P. Williams; R. Guzman; F. J. Castander

2004-07-20T23:59:59.000Z

439

BIO-OPTICAL PRESENTATIONS YEARS 2000 2004  

E-Print Network [OSTI]

BIO-OPTICAL PRESENTATIONS YEARS 2000 ­ 2004 YEAR 00-01 Armstrong, R.A., F. Gilbes, R. Guerrero. Lopez, and F. Gilbes, 2000, "Apparent Optical Properties at the Caribbean Time Station", Ocean Optics XV, Monaco. Gilbes, F., and R.A. Armstrong, 2000, "Inherent Optical Properties at the Caribbean Time Series

Gilbes, Fernando

440

Finite-temperature properties of one-dimensional hard-core bosons in a quasiperiodic optical lattice  

SciTech Connect (OSTI)

We investigate the properties of impenetrable bosons confined in a one-dimensional lattice at finite temperature in the presence of an additional incommensurate periodic potential. Relying on the exact Fermi-Bose mapping, we study the effects of temperature on the one-particle density matrix and related quantities such as the momentum distribution function and the natural orbitals. We found evidence of a finite-temperature crossover related to the zero-temperature superfluid-to-Bose-glass-transition that induces a delocalization of the lowest natural orbitals.

Nessi, Nicolas; Iucci, Anibal [Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata and IFLP-CONICET, CC 67, 1900 La Plata (Argentina)

2011-12-15T23:59:59.000Z

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441

Global observations of desert dust and biomass burning aerosols  

E-Print Network [OSTI]

Global observations of desert dust and biomass burning aerosols Martin de Graaf KNMI #12; Outline · Absorbing Aerosol Index - Theory · Absorbing Aerosol Index - Reality · Biomass burning.6 Biomass burning over Angola, 09 Sep. 2004 Absorbing Aerosol Index PMD image #12;biomass burning ocean

Graaf, Martin de

442

Infrared optical properties of amorphous and nanocrystalline Ta{sub 2}O{sub 5} thin films  

SciTech Connect (OSTI)

The optical constants of tantalum pentoxide (Ta{sub 2}O{sub 5}) are determined in a broad spectral region from the visible to the far infrared. Ta{sub 2}O{sub 5} films of various thicknesses from approximately 170 to 1600 nm are deposited using reactive magnetron sputtering on Si substrates. X-ray diffraction shows that the as-deposited films are amorphous, and annealing in air at 800 °C results in the formation of nanocrystalline Ta{sub 2}O{sub 5}. Ellipsometry is used to obtain the dispersion in the visible and near-infrared. Two Fourier-transform infrared spectrometers are used to measure the transmittance and reflectance at wavelengths from 1 to 1000 ?m. The surface topography and microstructure of the samples are examined using atomic force microscopy, confocal microscopy, and scanning electron microscopy. Classical Lorentz oscillators are employed to model the absorption bands due to phonons and impurities. A simple model is introduced to account for light scattering in the annealed films, which contain micro-cracks. For the unannealed samples, an effective-medium approximation is used to take into account the adsorbed moisture in the film and a Drude free-electron term is also added to model the broad background absorption.

Bright, T. J.; Watjen, J. I.; Zhang, Z. M. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)] [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Muratore, C. [Nanoelectronic Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson AFB, Ohio 45433 (United States) [Nanoelectronic Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson AFB, Ohio 45433 (United States); Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States); Voevodin, A. A. [Nanoelectronic Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson AFB, Ohio 45433 (United States)] [Nanoelectronic Materials Branch, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson AFB, Ohio 45433 (United States); Koukis, D. I.; Tanner, D. B. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Arenas, D. J. [Department of Physics, University of North Florida, Jacksonville, Florida 32254 (United States)] [Department of Physics, University of North Florida, Jacksonville, Florida 32254 (United States)

2013-08-28T23:59:59.000Z

443

Impact of Aerosols on Tropical Cyclones: An Investigation Using Convection-permitting Model Simulation  

SciTech Connect (OSTI)

The role of aerosols effect on two tropical cyclones over Bay of Bengal are investigated using a convection permitting model with two-moment mixed-phase bulk cloud microphysics scheme. The simulation results show the role of aerosol on the microphysical and dynamical properties of cloud and bring out the change in efficiency of the clouds in producing precipitation. The tracks of the TCs are hardly affected by the changing aerosol types, but the intensity exhibits significant sensitivity due to the change in aerosol contribution. It is also clearly seen from the analyses that higher heating in the middle troposphere within the cyclone center is in response to latent heat release as a consequence of greater graupel formation. Greater heating in the middle level is particularly noticeable for the clean aerosol regime which causes enhanced divergence in the upper level which, in turn, forces the lower level convergence. As a result, the cleaner aerosol perturbation is more unstable within the cyclone core and produces a more intense cyclone as compared to other two perturbations of aerosol. All these studies show the robustness of the concept of TC weakening by storm ingestion of high concentrations of CCN. The consistency of these model results gives us confidence in stating there is a high probability that ingestion of high CCN concentrations in a TC will lead to weakening of the storm but has little impact on storm direction. Moreover, as pollution is increasing over the Indian sub-continent, this study suggests pollution may be weakening TCs over the Bay of Bengal.

Hazra, Anupam; Mukhopadhyay, P.; Taraphdar, Sourav; Chen, J. P.; Cotton, William R.

2013-07-16T23:59:59.000Z

444

Phase correlations and optical coherence  

Science Journals Connector (OSTI)

We examine the properties of the recently introduced degrees of coherence regarding the phase correlations of the optical field. It is seen that some of these quantities are...

Tervo, Jani; Setälä, Tero; Friberg, Ari T

2012-01-01T23:59:59.000Z

445

First-principles calculations of the electronic structure and optical properties of K{sub 1-x}Na{sub x}TaO{sub 3} (x=0, 0.25, 0.5, 0.75, 1)  

SciTech Connect (OSTI)

The first-principles calculations are performed to investigate the cubic phase composite K{sub 1-x}Na{sub x}TaO{sub 3}(x=0, 0.25, 0.5, 0.75, 1), by using density functional theory (DFT) with the full potential linearized augmented plane wave (FP-LAPW) method. The energy band structures, density of states (DOS), electron density and optical properties are obtained. The results show that Na ion plays an important role in K{sub 1-x}Na{sub x}TaO{sub 3}. With the content of Na ion increasing, the changes of lattice parameters, energy gaps, bond lengths and optical properties of K{sub 1-x}Na{sub x}TaO{sub 3} are regular. Moreover, the dependence of ferroelectric photocatalysis on both optical properties and internal electronic structure are analyzed in detail. It is proposed that the doped materials are promising photocatalytic materials. - Graphical abstract: The density of states (DOS) of K{sub 1-x}Na{sub x}TaO{sub 3} (x=0.5). Highlights: Black-Right-Pointing-Pointer The first-principles calculations are performed, by using DFT with FP-LAPW method. Black-Right-Pointing-Pointer The changes of internal electronic structure and optical property of doped materials are regular. Black-Right-Pointing-Pointer The dependence of ferroelectric photocatalysis on optical properties is analyzed. Black-Right-Pointing-Pointer The dependence of ferroelectric photocatalysis on internal electronic structure is analyzed. Black-Right-Pointing-Pointer The doped materials are promising photocatalytic materials.

Zhao, Na [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China) [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); College of Science, National University of Defense Technology, Changsha 410073 (China); Wang, Yue-Hua, E-mail: wyhxxll@163.com [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China)] [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Wang, Qing-Xi; Hu, Wen-Jing [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China)] [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China)

2012-10-15T23:59:59.000Z