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1

Raman Lidar Profiles–Temperature (RLPROFTEMP) Value-Added Product  

SciTech Connect (OSTI)

The purpose of this document is to describe the Raman Lidar Profiles–Temperature (RLPROFTEMP) value-added product (VAP) and the procedures used to derive atmospheric temperature profiles from the raw RL measurements. Sections 2 and 4 describe the input and output variables, respectively. Section 3 discusses the theory behind the measurement and the details of the algorithm, including calibration and overlap correction.

Newsom, RK; Sivaraman, C; McFarlane, SA

2012-10-31T23:59:59.000Z

2

Raman lidar/AERI PBL Height Product  

SciTech Connect (OSTI)

Planetary Boundary Layer (PBL) heights have been computed using potential temperature profiles derived from Raman lidar and AERI measurements. Raman lidar measurements of the rotational Raman scattering from nitrogen and oxygen are used to derive vertical profiles of potential temperature. AERI measurements of downwelling radiance are used in a physical retrieval approach (Smith et al. 1999, Feltz et al. 1998) to derive profiles of temperature and water vapor. The Raman lidar and AERI potential temperature profiles are merged to create a single potential temperature profile for computing PBL heights. PBL heights were derived from these merged potential temperature profiles using a modified Heffter (1980) technique that was tailored to the SGP site (Della Monache et al., 2004). PBL heights were computed on an hourly basis for the period January 1, 2009 through December 31, 2011. These heights are provided as meters above ground level.

Ferrare, Richard

2012-12-14T23:59:59.000Z

3

Raman lidar/AERI PBL Height Product  

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

Planetary Boundary Layer (PBL) heights have been computed using potential temperature profiles derived from Raman lidar and AERI measurements. Raman lidar measurements of the rotational Raman scattering from nitrogen and oxygen are used to derive vertical profiles of potential temperature. AERI measurements of downwelling radiance are used in a physical retrieval approach (Smith et al. 1999, Feltz et al. 1998) to derive profiles of temperature and water vapor. The Raman lidar and AERI potential temperature profiles are merged to create a single potential temperature profile for computing PBL heights. PBL heights were derived from these merged potential temperature profiles using a modified Heffter (1980) technique that was tailored to the SGP site (Della Monache et al., 2004). PBL heights were computed on an hourly basis for the period January 1, 2009 through December 31, 2011. These heights are provided as meters above ground level.

Ferrare, Richard

4

Raman lidar and MPL Measurements during ALIVE  

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

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5

ARM: 10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm  

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

10-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

Newsom, Rob; Goldsmith, John

6

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

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

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

Sivaraman, Chitra; Flynn, Connor

7

ARM: 2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm  

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

2-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

Sivaraman, Chitra; Flynn, Connor

8

ARM: 10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm  

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

10-second Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

Sivaraman, Chitra; Flynn, Connor

9

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

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

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

Newsom, Rob; Goldsmith, John

10

ARM: 1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm  

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

1-minute Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

Sivaraman, Chitra; Flynn, Connor

11

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

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

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

Sivaraman, Chitra; Flynn, Connor

12

ARM: 10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm  

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

10-minute TEMPORARY Raman Lidar: aerosol scattering ratio and backscattering coefficient profiles, from first Ferrare algorithm

Sivaraman, Chitra; Flynn, Connor

13

DOE/SC-ARM/TR-120 Raman Lidar Profiles-Temperature  

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

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14

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

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

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

Newsom, Rob; Goldsmith, John

15

Raman lidar profiling of water vapor and aerosols over the ARM SGP Site  

SciTech Connect (OSTI)

The authors have developed and implemented automated algorithms to retrieve profiles of water vapor mixing ratio, aerosol backscattering, and aerosol extinction from Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) Raman Lidar data acquired during both daytime and nighttime operations. The Raman lidar sytem is unique in that it is turnkey, automated system designed for unattended, around-the-clock profiling of water vapor and aerosols. These Raman lidar profiles are important for determining the clear-sky radiative flux, as well as for validating the retrieval algorithms associated with satellite sensors. Accurate, high spatial and temporal resolution profiles of water vapor are also required for assimilation into mesoscale models to improve weather forecasts. The authors have also developed and implemented routines to simultaneously retrieve profiles of relative humidity. These routines utilize the water vapor mixing ratio profiles derived from the Raman lidar measurements together with temperature profiles derived from a physical retrieval algorithm that uses data from a collocated Atmospheric Emitted Radiance Interferometer (AERI) and the Geostationary Operational Environmental Satellite (GOES). These aerosol and water vapor profiles (Raman lidar) and temperature profiles (AERI+GOES) have been combined into a single product that takes advantage of both active and passive remote sensors to characterize the clear sky atmospheric state above the CART site.

Ferrare, R.A.

2000-01-09T23:59:59.000Z

16

RAMAN LIDAR PROFILING OF WATER VAPOR AND AEROSOLS OVER THE ARM SGP SITE.  

SciTech Connect (OSTI)

We have developed and implemented automated algorithms to retrieve profiles of water vapor mixing ratio, aerosol backscattering, and aerosol extinction from Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) Raman Lidar data acquired during both daytime and nighttime operations. This Raman lidar system is unique in that it is turnkey, automated system designed for unattended, around-the-clock profiling of water vapor and aerosols (Goldsmith et al., 1998). These Raman lidar profiles are important for determining the clear-sky radiative flux, as well as for validating the retrieval algorithms associated with satellite sensors. Accurate, high spatial and temporal resolution profiles of water vapor are also required for assimilation into mesoscale models to improve weather forecasts. We have also developed and implemented routines to simultaneously retrieve profiles of relative humidity. These routines utilize the water vapor mixing ratio profiles derived from the Raman lidar measurements together with temperature profiles derived from a physical retrieval algorithm that uses data from a collocated Atmospheric Emitted Radiance Interferometer (AERI) and the Geostationary Operational Environmental Satellite (GOES) (Feltz et al., 1998; Turner et al., 1999). These aerosol and water vapor profiles (Raman lidar) and temperature profiles (AERI+GOES) have been combined into a single product that takes advantage of both active and passive remote sensors to characterize the clear sky atmospheric state above the CART site.

FERRARE,R.A.

2000-01-09T23:59:59.000Z

17

Raman Lidar Profiles Best Estimate Value-Added Product Technical Report  

SciTech Connect (OSTI)

The ARM Raman lidars are semi-autonomous ground-based systems that transmit at a wavelength of 355 nm with 300 mJ, {approx}5 ns pulses, and a pulse repetition frequency of 30Hz. Signals from the various detection channels are processed to produce time- and height-resolved estimates of several geophysical quantities, such as water vapor mixing ratio, relative humidity, aerosol scattering ratio, backscatter, optical depth, extinction, and depolarization ratio. Data processing is currently handled by a suite of six value-added product (VAP) processes. Collectively, these processes are known as the Raman Lidar Profiles VAP (RLPROF). The top-level best-estimate (BE) VAP process was introduced in order to bring together the most relevant information from the intermediate-level VAPs. As such, the BE process represents the final stage in data processing for the Raman lidar. Its principal function is to extract the primary variables from each of the intermediate-level VAPs, perform additional quality control, and combine all of this information into a single output file for the end-user. The focus of this document is to describe the processing performed by the BE VAP process.

Newson, R

2012-01-18T23:59:59.000Z

18

Analysis and Calibration of CRF Raman Lidar Cloud Liquid Water Measurements  

SciTech Connect (OSTI)

The Atmospheric Radiation Measurement (ARM) Raman lidar (RL), located at the Southern Great Plains (SGP) Climate Research Facility (CRF), is a unique state-of-the-art active remote sensor that is able to measure profiles of water vapor, aerosol, and cloud properties at high temporal and vertical resolution throughout the diurnal cycle. In October 2005, the capability of the RL was extended by the addition of a new detection channel that is sensitive to the Raman scattering of liquid water. This new channel permits the system, in theory, to measure profiles of liquid water content (LWC) by the RL. To our knowledge, the ARM RL is the only operation lidar with this capability. The liquid water Raman backscattering cross-section is a relatively weak and spectrally broad feature, relative to the water vapor Raman backscatter signal. The wide bandpass required to achieve reasonable signal-to-noise in the liquid water channel essentially eliminates the ability to measure LWC profiles during the daytime in the presence of large solar background, and thus all LWC observations are nighttime only. Additionally, the wide bandpass increases the probability that other undesirable signals, such as fluorescence from aerosols, may contaminate the observation. The liquid water Raman cross-section has a small amount of overlap with the water vapor Raman cross-section, and thus there will be a small amount of ‘cross-talk’ between the two signals, with water vapor contributing a small amount of signal to the LWC observation. And finally, there is significant uncertainty in the actual strength of the liquid water Raman cross-section in the literature. The calibrated LWC profiles, together with the coincident cloud backscatter observations also made by the RL, can be used to derive profiles of cloud droplet effective radius. By combining these profiles of effective radius in the lower portion of the cloud with the aerosol extinction measurements made below the cloud by the RL, the first aerosol indirect effect can be investigated using a single instrument, thereby reducing the uncertainty associated with aligning the different sampling periods and fields of view of multiple instruments. We have applied a “first principles” calibration to the LWC profiles. This approach requires that the relative differences in optical efficiency between the water vapor and liquid water channels be known; this relative difference is easily computed using the efficiency values of the beam splitters and interference filters in the lidar that were provided by the vendors of these components. The first principles approach then transfers the calibration from the water vapor mixing ratio to the LWC using the difference in the optical efficiency and an interpolated value of the liquid water Raman cross section from the literature, and the better established water vapor Raman cross section. After accounting for all known error sources, the vertical integral of LWC was compared against a similar value retrieved from a co-located ground-based infrared radiometer. The RL and infrared radiometer have significantly different fields of view; thus to compare the two sensors the data were averaged to 5 min intervals where only cloudy samples were included in the average of each. While there is fair scatter in the data (r=0.47), there is also a clear indication of a positive correlation between the infrared and the RL values. The value of the slope of the regression is 0.49, which indicates a tendency of the RL measurements to underestimate the total liquid amount with respect to the infrared retrieval. Research continues to investigate the source of the bias, but the most likely candidate is the large uncertainty in the liquid water Raman cross-section as there have been no direct measurements made of this parameter at the lidar’s laser wavelength of 355 nm. The calibrated LWC profile was then used together with the cloud backscatter coefficient profile from the RL to derive profiles of cloud droplet effective radius and cloud droplet number density. These profiles o

Turner, D.D.

2007-10-31T23:59:59.000Z

19

Macrophysical Properties of Tropical Cirrus Clouds from the CALIPSO Satellite and from Ground-based Micropulse and Raman Lidars  

SciTech Connect (OSTI)

Lidar observations of cirrus cloud macrophysical properties over the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Darwin, Australia site are compared from the Cloud-Aerosol Lidar and In- frared Pathfinder Satellite Observation (CALIPSO) satellite, the ground-based ARM micropulse lidar (MPL), and the ARM Raman lidar (RL). Comparisons are made using the subset of profiles where the lidar beam is not fully attenuated. Daytime measurements using the RL are shown to be relatively unaffected by the solar background and are therefore suited for checking the validity of diurnal cycles. RL and CALIPSO cloud fraction profiles show good agreement while the MPL detects significantly less cirrus, particularly during the daytime. Both MPL and CALIPSO observations show that cirrus clouds occur less frequently during the day than at night at all altitudes. In contrast, the RL diurnal cy- cle is significantly different than zero only below about 11 km; where it is the opposite sign (i.e. more clouds during the daytime). For cirrus geomet- rical thickness, the MPL and CALIPSO observations agree well and both datasets have signficantly thinner clouds during the daytime than the RL. From the examination of hourly MPL and RL cirrus cloud thickness and through the application of daytime detection limits to all CALIPSO data we find that the decreased MPL and CALIPSO cloud thickness during the daytime is very likely a result of increased daytime noise. This study highlights the vast im- provement the RL provides (compared to the MPL) in the ARM program's ability to observe tropical cirrus clouds as well as a valuable ground-based lidar dataset for the validation of CALIPSO observations and to help im- prove our understanding of tropical cirrus clouds.

Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.; Sivaraman, Chitra; Vaughan, Mark A.; Winker, D.; Turner, David D.

2013-08-27T23:59:59.000Z

20

Turn-key Raman lidar for profiling atmospheric water vapor, clouds, and aerosols at the US Southern Great Plains Climate Study Site  

SciTech Connect (OSTI)

There are clearly identified scientific requirements for continuous profiling of atmospheric water vapor at the Department of Energy, Atmospheric Radiation Measurement program, Southern Great Plains CART (Cloud and Radiation Testbed) site in northern Oklahoma. Research conducted at several laboratories has demonstrated the suitability of Raman lidar for providing measurements that are an excellent match to those requirements. We have developed and installed a ruggedized Raman lidar system that resides permanently at the CART site, and that is computer automated to eliminate the requirements for operator interaction. In addition to the design goal of profiling water vapor through most of the troposphere during nighttime and through the boundary layer during daytime, the lidar provides quantitative characterizations of aerosols and clouds, including depolarization measurements for particle phase studies.

Goldsmith, J.E.M.; Blair, F.H.; Bisson, S.E.

1997-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Raman Lidar Measurements of Aerosols and Water Vapor During the May 2003 Aerosol IOP  

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

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22

Raman Lidar Receives Improvements  

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

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23

High Spectral Resolution Infrared and Raman Lidar Observations for the ARM Program: Clear and Cloudy Sky Applications  

SciTech Connect (OSTI)

This grant began with the development of the Atmospheric Emitted Radiance Interferometer (AERI) for ARM. The AERI has provided highly accurate and reliable observations of downwelling spectral radiance (Knuteson et al. 2004a, 2004b) for application to radiative transfer, remote sensing of boundary layer temperature and water vapor, and cloud characterization. One of the major contributions of the ARM program has been its success in improving radiation calculation capabilities for models and remote sensing that evolved from the multi-year, clear-sky spectral radiance comparisons between AERI radiances and line-by-line calculations (Turner et al. 2004). This effort also spurred us to play a central role in improving the accuracy of water vapor measurements, again helping ARM lead the way in the community (Turner et al. 2003a, Revercomb et al. 2003). In order to add high-altitude downlooking AERI-like observations over the ARM sites, we began the development of an airborne AERI instrument that has become known as the Scanning High-resolution Interferometer Sounder (Scanning-HIS). This instrument has become an integral part of the ARM Unmanned Aerospace Vehicle (ARM-UAV) program. It provides both a cross-track mapping view of the earth and an uplooking view from the 12-15 km altitude of the Scaled Composites Proteus aircraft when flown over the ARM sites for IOPs. It has successfully participated in the first two legs of the “grand tour” of the ARM sites (SGP and NSA), resulting in a very good comparison with AIRS observations in 2002 and in an especially interesting data set from the arctic during the Mixed-Phase Cloud Experiment (M-PACE) in 2004. More specifically, our major achievements for ARM include 1. Development of the Atmospheric Emitted Radiance Interferometer (AERI) to function like a satellite on the ground for ARM, providing a steady stream of accurately calibrated spectral radiances for Science Team clear sky and cloud applications (Knuteson et al. 2004a), 2. Detailed radiometric calibration and characterization of AERI radiances, with uncertainty estimates established from complete error analyses and proven by inter-comparison tests (Knuteson et al. 2004b), 3. AERI data quality assessment and maintenance over the extended time frames needed to support ARM (Dedecker et al., 2005) 4. Key role in the radiative transfer model improvements from the AERI/LBLRTM QME (Turner et al. 2004) and AERI-ER especially from the SHEBA experiment (Tobin et al. 1999), 5. Contributed scientific and programmatic leadership leading to significant water vapor accuracy improvements and uncertainty assessments for the low to mid troposphere (Turner et al. 2003a, Revercomb et al. 2003), 6. Leadership of the ARM assessment of the accuracy of water vapor observations from radiosondes, Raman Lidar and in situ aircraft observations in the upper troposphere and lower stratosphere (Tobin et al. 2002, Ferrare et al. 2004), 7. New techniques for characterizing clouds from AERI (DeSlover et al. 1999, Turner 2003b, Turner et al. 2003b), 8. Initial design and development of the Scanning-HIS aircraft instrument and application to ARM UAV Program missions (Revercomb et al. 2005), and 9. Coordinated efforts leading to the use of ARM observations as a key validation tool for the high resolution Atmospheric IR Sounder on the NASA Aqua platform (Tobin et al. 2005a) 10. Performed ARM site and global clear sky radiative closure studies that shows closure of top-of-atmosphere flux at the level of ~1 W/m2 (Moy et al 2008 and Section 3 of this appendix) 11. Performed studies to characterize SGP site cirrus cloud property retrievals and assess impacts on computed fluxes and heating rate profiles (Borg et al. 2008 and Section 2 of this appendix).

Henry Revercomb, David Tobin, Robert Knuteson, Lori Borg, Leslie Moy

2009-06-17T23:59:59.000Z

24

Lidar Report  

SciTech Connect (OSTI)

This report provides an overview of the LiDAR acquisition methodology employed by Woolpert on the 2009 USDA - Savannah River LiDAR Site Project. LiDAR system parameters and flight and equipment information is also included. The LiDAR data acquisition was executed in ten sessions from February 21 through final reflights on March 2, 2009; using two Leica ALS50-II 150kHz Multi-pulse enabled LiDAR Systems. Specific details about the ALS50-II systems are included in Section 4 of this report.

Wollpert.

2009-04-01T23:59:59.000Z

25

Raman Nanometrology of Graphene  

E-Print Network [OSTI]

13 Optical image of the graphene layers. . . . . .Micro-Raman Spectroscopy of Grapheneand Graphene Multi-Layers . . . . Raman Spectroscopy

Calizo, Irene Gonzales

2009-01-01T23:59:59.000Z

26

Micropulse Lidar (MPL) Handbook  

SciTech Connect (OSTI)

The micropulse lidar (MPL) is a ground-based optical remote sensing system designed primarily to determine the altitude of clouds overhead. The physical principle is the same as for radar. Pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is infered. Besides real-time detection of clouds, post-processing of the lidar return can also characterize the extent and properties of aerosol or other particle-laden regions.

Mendoza, A; Flynn, C

2006-05-01T23:59:59.000Z

27

ARM - PI Product - Raman lidar/AERI PBL Height Product  

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

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28

Doppler Lidar (DL) Handbook  

SciTech Connect (OSTI)

The Doppler lidar (DL) is an active remote sensing instrument that provides range- and time-resolved measurements of radial velocity and attenuated backscatter. The principle of operation is similar to radar in that pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is inferred. The radial or line-of-sight velocity of the scatterers is determined from the Doppler frequency shift of the backscattered radiation. The DL uses a heterodyne detection technique in which the return signal is mixed with a reference laser beam (i.e., local oscillator) of known frequency. An onboard signal processing computer then determines the Doppler frequency shift from the spectra of the heterodyne signal. The energy content of the Doppler spectra can also be used to determine attenuated backscatter.

Newsom, RK

2012-02-13T23:59:59.000Z

29

airborne oceanographic lidar: Topics by E-print Network  

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

Channels Landslides Spatial Cognition The emergence of airborne lidar data cognition and perception, we also explore the notion that the ongoing use of lidar enables...

30

Portable raman explosives detection  

SciTech Connect (OSTI)

Recent advances in portable Raman instruments have dramatically increased their application to emergency response and forensics, as well as homeland defense. This paper reviews the relevant attributes and disadvantages of portable Raman spectroscopy, both essentially and instrumentally, to the task of explosives detection in the field.

Moore, David Steven [Los Alamos National Laboratory; Scharff, Robert J [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

31

JOURNAL OF RAMAN SPECTROSCOPY J. Raman Spectrosc. 2005; 36: 864871  

E-Print Network [OSTI]

traditionally been utilized to indicate the phase transition. Comparisons with the Raman spectra of spodumene

Downs, Robert T.

32

Raman scattering in crystals  

SciTech Connect (OSTI)

A tutorial presentation is given of Raman scattering in crystals. The physical concepts are emphasized rather than the detailed mathematical formalism. Starting with an introduction to the concepts of phonons and conservation laws, the effects of photon-phonon interactions are presented. This interaction concept is shown for a simple cubic crystal and is extended to a uniaxial crystal. The correlation table method is used for determining the number and symmetry of the Raman active modes. Finally, examples are given to illustrate the relative ease of using this group theoretical method and the predictions are compared with measured Raman spectra. 37 refs., 17 figs., 6 tabs.

Edwards, D.F.

1988-09-30T23:59:59.000Z

33

Lidar characterization of crystalline silica generation and gravel plant  

E-Print Network [OSTI]

The lidar vertical pro?les and wind speed data were used toof wind speed and concentration (based on lidar verticalvertical plane at a given height, z, was calculated as the product of the wind speed

Trzepla-Nabaglo, K.; Shiraki, R.; Holm'en, B. A.

2006-01-01T23:59:59.000Z

34

Systematic Sampling of Scanning Lidar Swaths  

E-Print Network [OSTI]

Popescu Proof of concept lidar research has, to date, examined wall-to-wall models of forest ecosystems. While these studies have been important for verifying lidars efficacy for forest surveys, complete coverage is likely not the most cost effective... year of my graduate studies. Also, to Jin Zhu and the other members of the Aerial Photography project at the Texas Forest Service for opening my eyes to the practical uses of GIS and remote sensing, their encouragement for me to obtain a graduate...

Marcell, Wesley Tyler

2011-02-22T23:59:59.000Z

35

Micropulse Lidar Cloud Mask Value-Added Product Technical Report  

SciTech Connect (OSTI)

Lidar backscattered signal is a useful tool for identifying vertical cloud structure in the atmosphere in optically thin clouds. Cloud boundaries derived from lidar signals are a necessary input for popular ARM data products, such as the Active Remote Sensing of Clouds (ARSCL) product. An operational cloud boundary algorithm (Wang and Sassen 2001) has been implemented for use with the ARM Micropulse Lidar (MPL) systems. In addition to retrieving cloud boundaries above 500 m, the value-added product (VAP) named Micropulse Lidar Cloud Mask (MPLCMASK) applies lidar-specific corrections (i.e., range-square, background, deadtime, and overlap) as described in Campbell et al. (2002) to the measured backscattered lidar. Depolarization ratio is computed using the methodology developed by Flynn et al. (2007) for polarization-capable MPL systems. The cloud boundaries output from MPLCMASK will be the primary lidar cloud mask for input to the ARSCL product and will be applied to all MPL systems, including historical data sets.

Sivaraman, C; Comstock, J

2011-07-25T23:59:59.000Z

36

Raman accumulator as a fusion laser driver  

DOE Patents [OSTI]

Apparatus for simultaneous laser pulse amplification and compression, using multiple pass Raman scattering in one Raman cell and pulse switchout from the optical cavity through use of a dichroic device associated with the Raman cell.

George, E.V.; Swingle, J.C.

1982-03-31T23:59:59.000Z

37

E-Print Network 3.0 - airborne lidar measurements Sample Search...  

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

airborne INSAR is 2-5 m over... . However, LIDAR has potential as a complementary measurement to INSAR. The LIDAR data used in this study... estimate and the adjacent LIDAR ......

38

Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis  

SciTech Connect (OSTI)

This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

Meyer, Matthew W. [Ames Laboratory

2013-03-14T23:59:59.000Z

39

Superradiant Raman Laser Magnetometer  

E-Print Network [OSTI]

We demonstrate a proof-of-principle magnetometer that relies on the active oscillation of a cold atom Raman laser to continuously map a field-sensitive atomic phase onto the phase of the radiated light. We demonstrate wideband sensitivity during continuous active oscillation, as well as narrowband sensitivity in passive Ramsey-like mode with translation of the narrowband detection in frequency using spin-echo techniques. The sensor operates with a sensitivity of 190 pT/Hz^(1/2) at 1 kHz and effective sensing volume of 2 * 10^-3 mm^3. Fundamental quantum limits on the magnetic field sensitivity of an ideal detector are also considered.

Weiner, Joshua M; Bohnet, Justin G; Chen, Zilong; Thompson, James K

2012-01-01T23:59:59.000Z

40

Raman spectroscopy of shocked water  

SciTech Connect (OSTI)

Raman scattering has been used extensively to study the vibrational and rotational properties of molecules under a variety of conditions. Here, interest is in the behavior of water molecules shocked to high pressures and temperatures. Behind the shock front the water molecules undergo changes in bonding and the molecules may become ionized. Raman spectroscopy can be used to determine the molecular species behind the shock front. In addition, changes in Raman spectra can yield information regarding inter- and intramolecular potentials and the temperature behind the shock front.

Holmes, N.C.; Mitchell, A.C.; Nellis, W.J.; Graham, W.B.; Walrafen, G.E.

1983-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Lidar techniques for search and rescue  

SciTech Connect (OSTI)

Four techniques for using LIDAR in Search and Rescue Operations will be discussed. The topic will include laser retroreflection, laser-induced fluorescence in the visible, laser-induced fluorescence during daylight hours, and laser-induced fluorescence in the uv. These techniques use high-repetition rate lasers at a variety of frequencies to induce either fluorescence in dye markers or retroreflection from plastic corner cubes on life preservers and other emergency markers.

Cabral, W.L.

1985-01-01T23:59:59.000Z

42

2.1 RAMAN LIDAR PROFILING OF WATER VAPOR AND AEROSOLS OVER THE ARM SGP SITE  

E-Print Network [OSTI]

with satellite sensors. Accurate, high spatial and temporal resolution profiles of water vapor are also required+GOES) have been combined into a single product that takes advantage of both active and passive remote sensors with the use of narrowband (~0.4 nm bandpass) filters, reduces the background skylight and, therefore

43

Posters Scanning Raman Lidar Measurements of Atmospheric Water Vapor and Aerosols  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006PhotovoltaicSeptember 22, 2014SocietyJ. Dudhia51 Posters7551

44

Ris-PhD-Report Complex Terrain and Wind Lidars  

E-Print Network [OSTI]

calculations over the same terrains. The lidar performance was also simulated with the commercial software WAs;#12;Author: Ferhat Bingöl Title: Complex terrain and wind lidars Division: Wind Energy Division Risø-PhD-52 and the comparison of the measurement data with the flow model outputs showed that the mean wind speed calculated

45

EN-025 Tools & Applications December 2008 Lidar Remote Sensing  

E-Print Network [OSTI]

IS LIDAR? Lidar (light detection and ranging system) is a relatively new type of active remote sensing are small-footprint, discrete return systems that record two to five returns for each emitted laser pulse fashion as an aerial photography camera. · An inertial measurement unit that records the pitch, yaw

46

Ris {R{1127(EN) Lidar data used in the COFIN  

E-Print Network [OSTI]

3.1 Generation of arti cial smoke 7 4 Data processing 8 4.1 The lidar equation 8 4.2 Backscatter, see below. In FLADIS the smoke were added to an initial heavy gas plume. 2 Experimental design Figures response. However, the Lidar does have a averaging volume due to the leng

47

Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012  

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

Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

Jaffe, Todd

48

Micropulse Lidar The ARM Program studies  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergyInnovationMichaelGE1 Micropulse Lidar The ARM Program

49

JOURNAL OF RAMAN SPECTROSCOPY J. Raman Spectrosc. 2003; 34: 769775  

E-Print Network [OSTI]

Science (www.interscience.wiley.com). DOI: 10.1002/jrs.1051 Raman spectroscopic study of spodumene (LiAlSi2O6 spectrum of a natural specimen of the pyroxene spodumene, from its low-pressure (C2/c) to its high, was not observed. Copyright 2003 John Wiley & Sons, Ltd. KEYWORDS: spodumene; pyroxene; pressure-induced phase

Downs, Robert T.

50

Inversion-free, noiseless Raman echoes  

E-Print Network [OSTI]

Using double optical Raman rephasing, an inversion-free resonant Raman echo is studied in an inhomogeneously broadened spin ensemble of a solid medium, where the Raman optical field-excited spin coherence has a frozen propagation vector. Unlike photon echoes whose quantum memory application is strictly limited due to \\pi rephasing pulse-induced population inversion causing quantum noises, the optical Raman field-excited spin echo is inherently silent owing to the frozen propagation vector. Thus, the doubly rephased Raman echo can be directly applied for quantum interface in a population inversion-free environment.

Byoung S. Ham

2011-11-20T23:59:59.000Z

51

Intermodal entanglement in Raman processes  

E-Print Network [OSTI]

The operator solution of a completely quantum mechanical Hamiltonian of the Raman processes is used here to investigate the possibility of obtaining intermodal entanglement between different modes involved in the Raman processes (e.g. pump mode, Stokes mode, vibration (phonon) mode and anti-Stokes mode). Intermodal entanglement is reported between a) pump mode and anti-Stokes mode, b) pump mode and vibration (phonon) mode c) Stokes mode and vibration phonon mode, d) Stokes mode and anti-stokes mode in the stimulated Raman processes for the variation of the phase angle of complex eigenvalue $\\alpha_{1}$ of pump mode $a$. Some incidents of intermodal entanglement in the spontaneous and the partially spontaneous Raman processes are also reported. Further it is shown that the specific choice of coupling constants may produce genuine entanglement among Stokes mode, anti-Stokes mode and vibration-phonon mode. It is also shown that the two mode entanglement not identified by Duan's criterion may be identified by Hillery-Zubairy criteria. It is further shown that intermodal entanglement, intermodal antibunching and intermodal squeezing are independent phenomena.

Biswajit Sen; Sandip Kumar Giri; Swapan Mandal; C. H. Raymond Ooi; Anirban Pathak

2013-01-02T23:59:59.000Z

52

Atmospheric Data, Images, and Animations from Lidar Instruments used by the University of Wisconsin Lidar Group  

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

The Space Science and Engineering Center is a research and development center affiliated with the University of Wisconsin-Madison’s Graduate School. Its primary focus is on geophysical research and technology to enhance understanding of the atmosphere of Earth, the other planets in the Solar System, and the cosmos. SSEC develops new observing tools for spacecraft, aircraft, and ground-based platforms, and models atmospheric phenomena. The Center receives, manages and distributes huge amounts of geophysical data and develops software to visualize and manipulate these data for use by researchers and operational meteorologists all over the world.[Taken from About SSEC at http://www.ssec.wisc.edu/overview/] A huge collection of data products, images, and animations comes to the SSEC from the University of Wisconsin Lidar Group. Contents of this collection include: • An archive of thousands of Lidar images acquired before 2004 • Arctic HSRL, MMCR, PAERI, MWR, Radiosonde, and CRAS forecast data Data after May 1, 2004 • MPEG animations and Lidar Multiple Scattering Models

53

airborne lidar mapping: Topics by E-print Network  

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

A minimum height of 1 m was applied to define woody understorey. Critical to this process were a Digital Terrain Model (extracted from the leaf-off last return LiDAR data)...

54

URBAN MODELING FROM LIDAR DATA IN AN INTEGRATED GIS ENVIRONMENT  

E-Print Network [OSTI]

are analyzed and possible solutions are proposed by fusing lidar data with other image data. Study shows: it allows rapid generation large-scale DTM (digital terrain model); is daylight independent; is relatively

Shan, Jie

55

absorption lidar dial: Topics by E-print Network  

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

Topic Index 1 Development of an eye-safe diode-laser-based micro-pulse differential absorption lidar (MP-dial) for atmospheric water-vapor and aerosol studies. Open Access Theses...

56

A motor drive control system for the Lidar Polarimeter  

E-Print Network [OSTI]

A MOTOR DRIVE CONTROL SYSTEM FOR THE LIDAR POLARIMETER A Thesis by Waiming Leung Submitted to the Graduate College of Texas A/M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCF, May 1977 Major... Subject: Electrical Engineering A MOTOR DRIVE CONTROL SYSTEM FOR THE LIDAR POLARIMETER A Thesis by Waiming Leung Approved as to style and content by: Chairman o Comm' ee ea o epartment Member Mem er May 1977 ABSTRACT A Motor Drive Control...

Leung, Waiming

1977-01-01T23:59:59.000Z

57

LIDAR Wind Speed Measurements of Evolving Wind Fields  

SciTech Connect (OSTI)

Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

Simley, E.; Pao, L. Y.

2012-07-01T23:59:59.000Z

58

Mapping surface fuels using LIDAR and multispectral data fusion for fire behavior modeling  

E-Print Network [OSTI]

, LIDAR derived data provides accurate estimates of surface fuel parameters efficiently and accurately over extensive areas of forests. This study demonstrates the importance of using accurate maps of fuel models derived using new LIDAR remote sensing...

Mutlu, Muge

2009-05-15T23:59:59.000Z

59

Raman activity in synchronously dividing bacteria  

SciTech Connect (OSTI)

Using a spectrometer equipped with an optical-multichannel analyzer as the detector (OMA), we have observed the Stokes laser-Raman spectra of metabolically active Escherichia coli and Bacillus megaterium from 100 - 2100 cm/sup -1/. After lengthy investigation, no Raman lines attributable to the metabolic process nor the cells themselves were found. Previous Raman spectra of active bacteria cannot be used to support nonlinear theories in biology. 34 refs., 9 figs.

Layne, S.P.

1985-01-01T23:59:59.000Z

60

Geospatial analysis of vulnerable beach-foredune systems from decadal time series of lidar data  

E-Print Network [OSTI]

Geospatial analysis of vulnerable beach-foredune systems from decadal time series of lidar data, Geospatial analysis of vulnerable beach- foredune systems from decadal time series of lidar data, Journal densities; therefore, geospatial analysis, when applied to decadal lidar time series, needs to address

Mitasova, Helena

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Alternate spatial sampling approaches for ecosystem structure inventory using spaceborne lidar  

E-Print Network [OSTI]

used in aircraft lidar remote sensing where power, heat, and reliability are less of a concern since January 2011 Accepted 29 January 2011 Available online 23 March 2011 Keywords: Lidar Remote sensing Laser collected in transects and should be considered for future lidar remote sensing missions. © 2011 Elsevier

Lefsky, Michael

62

ARM: ARSCL: multiple outputs from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR  

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

ARSCL: multiple outputs from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

Coulter, Richard; Widener, Kevin; Bharadwaj, Nitin; Johnson, Karen; Martin, Timothy

63

ARM: ARSCL: cloud boundaries from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR  

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

ARSCL: cloud boundaries from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

Coulter, Richard; Widener, Kevin; Bharadwaj, Nitin; Johnson, Karen; Martin, Timothy

64

Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control: Preprint  

SciTech Connect (OSTI)

Turbine-mounted lidars provide preview measurements of the incoming wind field. By reducing loads on critical components and increasing the potential power extracted from the wind, the performance of wind turbine controllers can be improved [2]. As a result, integrating a light detection and ranging (lidar) system has the potential to lower the cost of wind energy. This paper presents an evaluation of turbine-mounted lidar availability. Availability is a metric which measures the proportion of time the lidar is producing controller-usable data, and is essential when a wind turbine controller relies on a lidar. To accomplish this, researchers from Avent Lidar Technology and the National Renewable Energy Laboratory first assessed and modeled the effect of extreme atmospheric events. This shows how a multirange lidar delivers measurements for a wide variety of conditions. Second, by using a theoretical approach and conducting an analysis of field feedback, we investigated the effects of the lidar setup on the wind turbine. This helps determine the optimal lidar mounting position at the back of the nacelle, and establishes a relationship between availability, turbine rpm, and lidar sampling time. Lastly, we considered the role of the wind field reconstruction strategies and the turbine controller on the definition and performance of a lidar's measurement availability.

Davoust, S.; Jehu, A.; Bouillet, M.; Bardon, M.; Vercherin, B.; Scholbrock, A.; Fleming, P.; Wright, A.

2014-05-01T23:59:59.000Z

65

Ris-R-Report LIDAR Wind Speed Measurements from a  

E-Print Network [OSTI]

, the spinner axis's vertical tilt and the wind turbine's yaw relative to the mean wind speed direction: Data Files 54 Appendix B: Wind Speed Vertical Profile 55 Appendix C: Sonic Cup Comparison 59Risø-R-Report LIDAR Wind Speed Measurements from a Rotating Spinner: "SpinnerEx 2009" Nikolas

66

FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES  

E-Print Network [OSTI]

FIRST PRINCIPLES MODELING FOR LIDAR SENSING OF COMPLEX ICE SURFACES J. Kerekes, A. Goodenough, S of monitoring the dynamics and mass balance of glaciers, ice caps, and ice sheets. However, it is also known that ice surfaces can have complex 3-dimensional structure, which can challenge their accurate retrieval

Kerekes, John

67

Lidar on the Phoenix mission to Mars James Whiteway,1  

E-Print Network [OSTI]

Cameron Dickinson,1 Leonce Komguem,1 and Clive Cook1 Received 30 August 2007; revised 9 March 2008 of backscattered laser light from airborne dust and clouds. These observations will be coordinated with solar, and C. Cook (2008), Lidar on the Phoenix mission to Mars, J. Geophys. Res., 113, E00A08, doi:10

Duck, Thomas J.

68

absorption lidar performance: Topics by E-print Network  

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

absorption lidar performance First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Development of a...

69

absorption lidar sensitivity: Topics by E-print Network  

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

absorption lidar sensitivity First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Development of a...

70

absorption lidar system: Topics by E-print Network  

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

absorption lidar system First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Development of a differential...

71

INTEGRATED LIDAR & PHOTOGRAMMETRIC DOCUMENTATION OF THE RED GULCH DINOSAUR  

E-Print Network [OSTI]

101 INTEGRATED LIDAR & PHOTOGRAMMETRIC DOCUMENTATION OF THE RED GULCH DINOSAUR TRACKSITE (WYOMING Resource Technology Section, National Operations Center, Bu- reau of Land Management, Bldg. 50 Denver, CO of successful schemes is testament to the advances made in attitudes and approaches to fossil site management

Falkingham, Peter

72

Inelastic neutron and low-frequency Raman scattering in a niobium-phosphate glass for Raman gain applications  

E-Print Network [OSTI]

Inelastic neutron and low-frequency Raman scattering in a niobium-phosphate glass for Raman gain: Raman scattering; Neutron scattering; Raman gain; Boson peak We present measurements of the vibrational, extracted from specific-heat or neutron scattering measurements [7,8]. Only very recently two of the present

Schirmacher, Walter

73

The vibrational Raman spectrum of CS?  

E-Print Network [OSTI]

THE VIBRATIONAL RAMAN SPECTRUM OF CSp A Thesis By HAROLD NOBLE BALLARD Approved as to style and content by Chairman o| Committee THE VIBRATIONAL RAMAN SPECTRUM OF CS2 HAROLD NOBLE BALLARD A Thesis Suhmitted to the Graduate School... in the procurement of necessary equipment. SECTION I: INTRODUCTION. SECTION II: CLASSICAL THEORY OF RAHAM SCATTERING . SECTION III: THEORY OF NORMAL VIBRATIONS AND VIBRATIONAL WAVE EQUATIONS. A, Morsel Vibrations B. Vibrational Wave Eqnation and lhergy Levels...

Ballard, Harold Noble

1950-01-01T23:59:59.000Z

74

High fidelity nanohole enhanced Raman spectroscopy.  

SciTech Connect (OSTI)

Surface enhanced Raman spectroscopy (SERS) is a sensitive technique that can even detect single molecules. However, in many SERS applications, the strongly inhomogeneous distribution of intense local fields makes it very difficult for a quantitive assessment of the fidelity, or reproducibility of the signal, which limits the application of SERS. Herein, we report the development of exceptionally high-fidelity hole-enhanced Raman spectroscopy (HERS) from ordered, 2D hexagonal nanohole arrays. We take the fidelity f to be a measure of the percent deviation of the Raman peaks from measurement to measurement. Overall, area averaged fidelities for 12 gold array samples ranged from f {approx} 2-15% for HERS using aqueous R6G molecules. Furthermore, intensity modulations of the enhanced Raman spectra were measured for the first time as a function of polarization angle. The best of these measurements, which focus on static laser spots on the sample, could be consistent with even higher fidelities than the area-averaged results. Nanohole arrays in silver provided supporting polarization measurements and a more complete enhanced Raman fingerprint for phenylalanine molecules. We also carried out finite-difference time-domain calculations to assist in the interpretation of the experiments, identifying the polarization dependence as possibly arising from hole-hole interactions. Our results represent a step toward making quantitative and reproducible enhanced Raman measurements possible and also open new avenues for a large-scale source of highly uniform hot spots.

Bahns, J. T.; Guo, Q.; Gray, S. K.; Jaeger, H. M.; Chen, L.; Montgomery, J. M.; Univ. of Chicago

2009-01-01T23:59:59.000Z

75

Assessment and Optimization of Lidar Measurement Availability for Wind Turbine Control (Poster)  

SciTech Connect (OSTI)

Integrating Lidar to improve wind turbine controls is a potential breakthrough for reducing the cost of wind energy. By providing undisturbed wind measurements up to 400m in front of the rotor, Lidar may provide an accurate update of the turbine inflow with a preview time of several seconds. Focusing on loads, several studies have evaluated potential reductions using integrated Lidar, either by simulation or full scale field testing.

Scholbrock, F. A.; Fleming, P.; Wright, A.; Davoust, S.; Jehu, A.; Bouillet, M.; Bardon M.; Vercherin, B.

2014-02-01T23:59:59.000Z

76

SciTech Connect: Field Test Results from Lidar Measured Yaw Control...  

Office of Scientific and Technical Information (OSTI)

Conference: Field Test Results from Lidar Measured Yaw Control for Improved Yaw Alignment with the NREL Controls Advanced Research Turbine: Preprint Citation Details In-Document...

77

Structural Analysis of Southern Dixie Valley using LiDAR and...  

Open Energy Info (EERE)

Structural Analysis of Southern Dixie Valley using LiDAR and Low-Sun-Angle Aerial Photography, NAS Fallon Geothermal Exploration Project, Dixie Valley, Nevada Jump to: navigation,...

78

Comparison of temperature and humidity profiles with elastic-backscatter lidar data  

SciTech Connect (OSTI)

This contribution analyzes elastic-backscatter lidar data and temperature and humidity profiles from radiosondes acquired in Barcelona in July 1992. Elastic-backscatter lidar data reveal the distribution of aerosols within the volume of atmosphere scanned. By comparing this information with temperature and humidity profiles of the atmosphere at a similar time, we are able to asses de relationship among aerosol distribution and atmospheric stability or water content, respectively. Comparisons have shown how lidar`s revealed layers of aerosols correspond to atmospheric layers with different stability condition and water content.

Soriano, C. [Universidad Politecnica de Cataluna, Barcelona (Spain)]|[Los Alamos National Lab., NM (United States); Buttler, W.T. [Los Alamos National Lab., NM (United States); Baldasano, J.M. [Universidad Politecnica de Cataluna, Barcelona (Spain)

1995-04-01T23:59:59.000Z

79

Tunable infrared source employing Raman mixing  

DOE Patents [OSTI]

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

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

1980-01-01T23:59:59.000Z

80

Tracking Honey Bees Using LIDAR (Light Detection and Ranging) Technology  

SciTech Connect (OSTI)

The Defense Advanced Research Projects Agency (DARPA) has recognized that biological and chemical toxins are a real and growing threat to troops, civilians, and the ecosystem. The Explosives Components Facility at Sandia National Laboratories (SNL) has been working with the University of Montana, the Southwest Research Institute, and other agencies to evaluate the feasibility of directing honeybees to specific targets, and for environmental sampling of biological and chemical ''agents of harm''. Recent work has focused on finding and locating buried landmines and unexploded ordnance (UXO). Tests have demonstrated that honeybees can be trained to efficiently and accurately locate explosive signatures in the environment. However, it is difficult to visually track the bees and determine precisely where the targets are located. Video equipment is not practical due to its limited resolution and range. In addition, it is often unsafe to install such equipment in a field. A technology is needed to provide investigators with the standoff capability to track bees and accurately map the location of the suspected targets. This report documents Light Detection and Ranging (LIDAR) tests that were performed by SNL. These tests have shown that a LIDAR system can be used to track honeybees. The LIDAR system can provide both the range and coordinates of the target so that the location of buried munitions can be accurately mapped for subsequent removal.

BENDER, SUSAN FAE ANN; RODACY, PHILIP J.; SCHMITT, RANDAL L.; HARGIS JR., PHILIP J.; JOHNSON, MARK S.; KLARKOWSKI, JAMES R.; MAGEE, GLEN I.; BENDER, GARY LEE

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Short-range, Non-contact Detection of Surface Contamination Using Raman Lidar Arthur J. Sedlacek, III*  

E-Print Network [OSTI]

-time detection and identification of bulk amounts of substances on surfaces. Optical spectroscopic methods detection and identification of chemical spills is discussed. The new chemical sensor combines the spectral-range (meters to tens of meters), non-contact detection and identification of unknown substances on surfaces

82

DOE/SC-ARM/TR-100 Raman Lidar Profiles Best Estimate Value-Added Product Technical Report  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases onOrganizationElectronic Reading2Q)38232 Revision 1SC6099359380

83

Ultraviolet Resonant Raman Enhancements in the Detection of Explosives  

SciTech Connect (OSTI)

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

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

2009-06-03T23:59:59.000Z

84

ARM: ARSCL: cloud base height from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR  

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

ARSCL: cloud base height from first Clothiaux algorithms on Vaisala or Belfort ceilometers, Micropulse lidar, and MMCR

Coulter, Richard; Widener, Kevin; Bharadwaj, Nitin; Johnson, Karen; Martin, Timothy

85

All Sky Camera, LIDAR and Electric Field Meter: auxiliary instruments for the ASTRI SST-2M prototype  

E-Print Network [OSTI]

ASTRI SST-2M is the end-to-end prototype telescope of the Italian National Institute of Astro- physics, INAF, designed to investigate the 10-100 TeV band in the framework of the Cherenkov Telescope Array, CTA. The ASTRI SST-2M telescope has been installed in Italy in September 2014, at the INAF ob- serving station located at Serra La Nave on Mount Etna. The telescope is foreseen to be completed and fully operative in spring 2015 including auxiliary instrumentation needed to support both operations and data anal- ysis. In this contribution we present the current status of a sub-set of the auxiliary instruments that are being used at the Serra La Nave site, namely an All Sky Camera, an Electric Field Meter and a Raman Lidar devoted, together with further instrumentation, to the monitoring of the atmospheric and environmental conditions. The data analysis techniques under development for these instruments could be applied at the CTA sites, where similar auxiliary instrumentation will be installed.

Leto, Giuseppe; Bellassai, Giancarlo; Bruno, Pietro; Maccarone, Maria Concetta; Martinetti, Eugenio

2015-01-01T23:59:59.000Z

86

Real-time Raman system for in vivo disease diagnosis  

E-Print Network [OSTI]

Raman spectroscopy has been well established as a powerful in vitro method for studying biological tissue and diagnosing disease. The recent development of efficient, high-throughput, low-background optical fiber Raman ...

Motz, Jason T.

87

Absolute Raman matrix elements of graphene and graphite  

E-Print Network [OSTI]

Using sample substitution [Grimsditch et al., J. Raman Spectrosc. 10, 77 (1981)] we deconvolve the highly wavelength-dependent response of the spectrometer from the Raman spectra of graphene suspended on an SiO[subscript ...

Reich, Stephanie

88

Raman and surface-enhanced Raman study of asymmetrically substituted viologens  

SciTech Connect (OSTI)

The normal Raman (NR), resonance Raman (RR), surface-enhanced Raman scattering (SERS), and surface-enhanced resonance Raman scattering (SERRS) spectra of the three redox forms of several asymmetric viologens, N-octyl-N'-methylviologen (C/sub 8/MV), N-dodecyl-N'-methylviologen (C/sub 12/MV), and N-hexadecyl-N'-methylviologen (C/sub 16/MV), have been characterized and compared with the corresponding spectra of the three redox forms of methylviologen (MV). It was observed that the substituents of the two N atoms of the viologen do not affect its overall symmetry. Only the Raman bands near 1200 cm/sup /minus/1/, containing major contributions from the N-alkyl stretching vibrations, are affected by the asymmetric substitution. The RR spectra of both the monomer and dimer forms of the cation radicals were obtained by varying the experimental conditions used in their preparation. As previously observed for MV, dimerization of the asymmetric viologen radicals produces splitting of certain RR bands. Resonance Raman spectra of the fully reduced viologens were also obtained and used to monitor the disproportionation reaction between the dication and fully reduced form of the viologen. Surface-enhanced Raman and SERRS spectra of the different asymmetric viologens were found to vary slightly due to changes in their adsorption behavior with increasing chain length of the alkyl substituent.

Lu, T.; Cotton, T.M.; Hurst, J.K.; Thompson, D.H.P.

1988-12-01T23:59:59.000Z

89

Remote adjustable focus Raman spectroscopy probe  

DOE Patents [OSTI]

A remote adjustable focus Raman spectroscopy probe allows for analyzing Raman scattered light from a point of interest external probe. An environmental barrier including at least one window separates the probe from the point of interest. An optical tube is disposed adjacent to the environmental barrier and includes a long working length compound lens objective next to the window. A beam splitter and a mirror are at the other end. A mechanical means is used to translated the prove body in the X, Y, and Z directions resulting in a variable focus optical apparatus. Laser light is reflected by the beam splitter and directed toward the compound lens objective, then through the window and focused on the point of interest. Raman scattered light is then collected by the compound lens objective and directed through the beam splitter to a mirror. A device for analyzing the light, such as a monochrometer, is coupled to the mirror.

Schmucker, John E. (Hurt, VA); Blasi, Raymond J. (Harrison City, PA); Archer, William B. (Bethel Park, PA)

1999-01-01T23:59:59.000Z

90

Double resonance surface enhanced Raman scattering substrates: an intuitive coupled  

E-Print Network [OSTI]

. Westcott, L. R. Hirsch, J. L. West, and N. J. Halas, "Controlling the surface enhanced Raman effect via

91

LiDAR observations of offshore winds at future wind turbine operating heights  

E-Print Network [OSTI]

LiDAR observations of offshore winds at future wind turbine operating heights Alfredo Peña1 , Sven at the Horns Rev offshore wind farm. The influence of atmospheric stability on the surface layer wind shear: Charnock, LiDAR, Marine boundary layer, Offshore, Surface layer, Wind profile. 1 Introduction There is

92

Turbine Reliability and Operability Optimization through the use of Direct Detection Lidar Final Technical Report  

SciTech Connect (OSTI)

The goal of this Department of Energy (DOE) project is to increase wind turbine efficiency and reliability with the use of a Light Detection and Ranging (LIDAR) system. The LIDAR provides wind speed and direction data that can be used to help mitigate the fatigue stress on the turbine blades and internal components caused by wind gusts, sub-optimal pointing and reactionary speed or RPM changes. This effort will have a significant impact on the operation and maintenance costs of turbines across the industry. During the course of the project, Michigan Aerospace Corporation (MAC) modified and tested a prototype direct detection wind LIDAR instrument; the resulting LIDAR design considered all aspects of wind turbine LIDAR operation from mounting, assembly, and environmental operating conditions to laser safety. Additionally, in co-operation with our partners, the National Renewable Energy Lab and the Colorado School of Mines, progress was made in LIDAR performance modeling as well as LIDAR feed forward control system modeling and simulation. The results of this investigation showed that using LIDAR measurements to change between baseline and extreme event controllers in a switching architecture can reduce damage equivalent loads on blades and tower, and produce higher mean power output due to fewer overspeed events. This DOE project has led to continued venture capital investment and engagement with leading turbine OEMs, wind farm developers, and wind farm owner/operators.

Johnson, David K; Lewis, Matthew J; Pavlich, Jane C; Wright, Alan D; Johnson, Kathryn E; Pace, Andrew M

2013-02-01T23:59:59.000Z

93

Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology  

E-Print Network [OSTI]

#12;Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology Arlen F. Chasea,1. The impor- tance of this geospatial innovation is demonstrated with newly acquired LiDAR data from in the remote geospatial imaging of cultural landscapes, including ancient communities and their anthropogenic

Weishampel, John F.

94

A new cloud and aerosol layer detection method based on micropulse lidar measurements  

E-Print Network [OSTI]

A new cloud and aerosol layer detection method based on micropulse lidar measurements Chuanfeng algorithm to detect aerosols and clouds based on micropulse lidar measurements. A semidiscretization is then introduced. Combined with empirical threshold values, we determine if the signal waves indicate clouds

Li, Zhanqing

95

Modeling Residential Urban Areas from Dense Aerial LiDAR Point Clouds  

E-Print Network [OSTI]

Modeling Residential Urban Areas from Dense Aerial LiDAR Point Clouds Qian-Yi Zhou and Ulrich models for residential areas from aerial LiDAR scans. The key differ- ence between downtown area modeling and residential area modeling is that the latter usually contains rich vegetation. Thus, we propose a robust

Shahabi, Cyrus

96

Complete Residential Urban Area Reconstruction from Dense Aerial LiDAR Point Clouds  

E-Print Network [OSTI]

Complete Residential Urban Area Reconstruction from Dense Aerial LiDAR Point Clouds Qian-Yi Zhou area modeling and residential area modeling is that the latter usually con- tains rich vegetation. Thus representing the 3D urban reality of residential areas. Keywords: urban modeling, LiDAR, residential area

Shahabi, Cyrus

97

Vibrational Raman Spectroscopy of High-temperature Superconductors  

E-Print Network [OSTI]

Vibrational Raman Spectroscopy of High-temperature Superconductors C. Thomsen and G. Kaczmarczyk-temperature Superconductors C. Thomsen and G. Kaczmarczyk Technical University of Berlin, Berlin, Germany 1 INTRODUCTION Raman after the discovery of high- critical-temperature Tc superconductors:2 while reports on Raman scattering

Nabben, Reinhard

98

Human brain cancer studied by resonance Raman spectroscopy  

E-Print Network [OSTI]

Human brain cancer studied by resonance Raman spectroscopy Yan Zhou Cheng-Hui Liu Yi Sun Yang Pu://biomedicaloptics.spiedigitallibrary.org/ on 11/16/2012 Terms of Use: http://spiedl.org/terms #12;Human brain cancer studied by resonance Raman of human brain tissues are examined using a confocal micro-Raman system with 532-nm excitation in vitro

Sun, Yi

99

Special Section Guest Editorial Coherent Raman Imaging Techniques and Biomedical  

E-Print Network [OSTI]

Special Section Guest Editorial Coherent Raman Imaging Techniques and Biomedical Applications. The combination of high resolution and molecular contrast has moved Raman techniques into the biomedical spotlight on biomedical imag- ing. The spontaneous Raman interaction is weak, yielding insufficient photons for fast

Potma, Eric Olaf

100

Raman laser with controllable suppression of parasitics  

DOE Patents [OSTI]

Method and apparatus for switching energy out of a Raman laser optical cavity. Coherent radiation at both the pump and first Stokes wave frequencies are introduced into the optical cavity from the same direction, and a second Stokes wave is utilized to switch the energy out of the cavity.

George, E. Victor (Livermore, CA)

1986-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Lidar Inter-Comparison Exercise Final Campaign Report A Protat  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs spaceLaser TheLessons LearnedLibraryTeamingLidar

102

Complex-optical-field lidar system for range and vector velocity measurement  

E-Print Network [OSTI]

Complex-optical-field lidar system for range and vector velocity measurement Shuang Gao,1,2 Maurice O’Sullivan,3 and Rongqing Hui2,* 1Department of Electronic Engineering and Information Science, University of Science and Technology of China... lidar system based on the measurement of complex optical field is demonstrated for the first time. An electro-optic in- phase/quadrature (I/Q) modulator is used in the lidar transmitter to realize carrier-suppressed complex optical field modulation...

Gao, Shuang; Sullivan, Maurice O.; Hui, Rongqing

2012-11-01T23:59:59.000Z

103

Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships  

E-Print Network [OSTI]

comparison of mineral dust aerosol retrievals from two instruments, MODIS and CALIPSO lidar. And, we implement and evaluate a new mineral dust detection algorithm based on the analysis of thin dust radiative signature. In comparison, three commonly used...

Cho, Hyoun-Myoung

2012-02-14T23:59:59.000Z

104

Accessing the Energy Department’s Lidar Buoy Data off Virginia Beach  

Broader source: Energy.gov [DOE]

In December 2014, Pacific Northwest National Laboratory (PNNL) deployed the Energy Department’s floating lidar buoy off of Virginia Beach, Virginia, in less than 30 meters (m) of water,...

105

SciTech Connect: Field Test Results from Lidar Measured Yaw Control...  

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

This bias could be caused by a number of issues such as: poor calibration, electromagnetic interference, rotor wake, or other effects. With a lidar mounted on the nacelle, a...

106

NESTED HIGH RESOLUTION SIMULATION AND LIDAR VALIDATION OF A LAND BREEZE CIRCULATION  

E-Print Network [OSTI]

NESTED HIGH RESOLUTION SIMULATION AND LIDAR VALIDATION OF A LAND BREEZE CIRCULATION by GIJS DE BOER local forcing. A wide range of scales is simulated using the nesting capability of the University

Eloranta, Edwin W.

107

Development of a lidar polarimeter technique of measuring suspended solids in water  

E-Print Network [OSTI]

DEVELOPMENT OF A LIDAR POLARIMETER TECHNIQUE OF MEASURING SUSPENDED SOLIDS IN WATER A Thesis by DAVID W. PRESLEY Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1980 Major Subject; Electrical Engineering DEVELOPMENT OF A LIDAR POLARIMETER TECHNIQUE OF MEASURING SUSPENDED SOLIDS IN WATER A Thesis by DAVID W, PRESLEY Approved as to sty1e and content by: Chairman of Committee H d of Department...

Presley, David W

1980-01-01T23:59:59.000Z

108

Graphene and its derivatives : fabrication and Raman spectroscopy study.  

E-Print Network [OSTI]

??This thesis presents results on fabrication and Raman spectroscopy studies of graphene and its derivates. The works can be divided into two parts as follows.… (more)

Cong, Chunxiao.

2012-01-01T23:59:59.000Z

109

Combining Raman Microprobe and XPS to Study High Temperature...  

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

spectroscopy. Citation: Windisch CF, Jr, CH Henager, MH Engelhard, and WD Bennett.2011."Combining Raman Microprobe and XPS to Study High Temperature Oxidation of...

110

Raman and XPS characterization of fuel-cladding interactions...  

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

MOX fuel mixtures. Citation: Windisch CF, Jr, CH Henager, Jr, MH Engelhard, and WD Bennett.2009."Raman and XPS characterization of fuel-cladding interactions using miniature...

111

Inelastic neutron scattering, Raman and DFT investigations of...  

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

Inelastic neutron scattering, Raman and DFT investigations of the adsorption of phenanthrenequinone on onion-like carbon Daniela M. Anjos a , Alexander I. Kolesnikov a , Zili Wu a...

112

An Atmospheric Radiation Measurement Value-Added Product to Retrieve Optically Thin Cloud Visible Optical Depth using Micropulse Lidar  

SciTech Connect (OSTI)

The purpose of the Micropulse Lidar (MPL) Cloud Optical Depth (MPLCOD) Value-Added Product (VAP) is to retrieve the visible (short-wave) cloud optical depth for optically thin clouds using MPL. The advantage of using the MPL to derive optical depth is that lidar is able to detect optically thin cloud layers that may not be detected by millimeter cloud radar or radiometric techniques. The disadvantage of using lidar to derive optical depth is that the lidar signal becomes attenuation limited when ? approaches 3 (this value can vary depending on instrument specifications). As a result, the lidar will not detect optically thin clouds if an optically thick cloud obstructs the lidar beam.

Lo, C; Comstock, JM; Flynn, C

2006-10-01T23:59:59.000Z

113

MODIFYING AN INVERTED LABORATORY MICROSCOPE FOR RAMAN Presented in Partial Fulfillment of the Requirements for  

E-Print Network [OSTI]

MODIFYING AN INVERTED LABORATORY MICROSCOPE FOR RAMAN MICROSCOPY A Thesis Presented in Partial modifications a spectroscopic imaging instrument, a Raman microscope, can be constructed from a common inverted

114

E-Print Network 3.0 - adeep-ultraviolet resonance raman Sample...  

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

Maruyama Summary: Temperature dependence of resonance Raman of single-walled carbon nanotubes Shohei Chiashi... , Mototeru Oba and Shigeo Maruyama Raman scattering from...

115

E-Print Network 3.0 - anti-stokes raman spectroscopic Sample...  

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

a coherent anti-Stokes Raman spectroscopic imaging device in which two laser pulse trains... . August 19, 2008 System and method for coherent anti-Stokes Raman scattering...

116

Optical pumping via incoherent Raman transitions  

E-Print Network [OSTI]

A new optical pumping scheme is presented that uses incoherent Raman transitions to prepare a trapped Cesium atom in a specific Zeeman state within the 6S_{1/2}, F=3 hyperfine manifold. An important advantage of this scheme over existing optical pumping schemes is that the atom can be prepared in any of the F=3 Zeeman states. We demonstrate the scheme in the context of cavity quantum electrodynamics, but the technique is equally applicable to a wide variety of atomic systems with hyperfine ground-state structure.

A. D. Boozer; R. Miller; T. E. Northup; A. Boca; H. J. Kimble

2007-10-04T23:59:59.000Z

117

Quantum-entanglement-initiated super Raman scattering  

SciTech Connect (OSTI)

It has now been possible to prepare a chain of ions in an entangled state and thus the question arises: How will the optical properties of a chain of entangled ions differ from say a chain of independent particles? We investigate nonlinear optical processes in such chains. Since light scattering is quite a versatile technique to probe matter, we explicitly demonstrate the possibility of entanglement-produced super Raman scattering. Our results suggest the possibility of similar enhancement factors in other nonlinear processes like four-wave mixing.

Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2011-02-15T23:59:59.000Z

118

CLIENT : INDIAN ACADEMY OF SCIENCES C. V. RAMAN AVENUE,  

E-Print Network [OSTI]

CLIENT : INDIAN ACADEMY OF SCIENCES C. V. RAMAN AVENUE, SADASHIVNAGAR, BANGALORE ­ 560080 TENDER : PROPOSED INTERIORS FOR CABIN CUM MEETING ROOM AT INDIAN ACADEMY OF SCIENCES, C V RAMAN AVENUE, BANGALORE COMPLEX, KAMARAJ ROAD, II CROSS, BANGALORE - 560042 #12;INDIAN ACADEMY OF SCIENCES BANGALORE ­ 560080

Joshi, Yogesh Moreshwar

119

Raman Measurements on Electrochemically Doped Single-Walled Carbon Nanotubes  

E-Print Network [OSTI]

Raman Measurements on Electrochemically Doped Single-Walled Carbon Nanotubes P. M. Rafailov, M and studied the Raman response of electro- chemically doped single-walled carbon nanotubes (SWNT) using different salt solutions. The fre- quency shift of the radial breathing mode (RBM) and the high-energy mode

Nabben, Reinhard

120

Hydrogen Raman shifts in carbon nanotubes from molecular dynamics simulation  

E-Print Network [OSTI]

Hydrogen Raman shifts in carbon nanotubes from molecular dynamics simulation S.J.V. Frankland *, D hydrogen in individual single-shell carbon nanotubes and nanotube ropes using a semiclassical model. The calculations predict that isolated hydrogen molecules inside of nanotubes have a Raman frequency that increases

Brenner, Donald W.

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Deriving a Framework for Estimating Individual Tree Measurements with Lidar for Use in the TAMBEETLE Southern Pine Beetle Infestation Growth Model  

E-Print Network [OSTI]

. TAMBEETLE was used to compare spot growth between a lidar-derived forest map and a forest map generated by TAMBEETLE, based on sample plot characteristics. The lidar-derived forest performed comparably to the TAMBEETLE generated forest. Using lidar to map...

Stukey, Jared D.

2011-02-22T23:59:59.000Z

122

Simple Doppler Wind Lidar adaptive observation experiments with 3D-Var and an ensemble Kalman filter in a global primitive equations model  

E-Print Network [OSTI]

the next few years, the first Doppler Wind Lidar (DWL) will be deployed in space by the European Space1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Simple Doppler Wind Lidar adaptive Experiments, we compare several adaptive observation strategies designed to subsample Doppler Wind Lidar (DWL

Maryland at College Park, University of

123

Remote control and telescope auto-alignment system for multiangle LIDAR under development at CEILAP, Argentina  

E-Print Network [OSTI]

At CEILAP (CITEDEF-CONICET), a multiangle LIDAR is under development to monitor aerosol extinction coefficients in the frame of the CTA (Cherenkov Telescope Array) Project. This is an initiative to build the next generation of ground-based instruments to collect very high energy gamma-ray radiation (>10 GeV). The atmospheric conditions are very important for CTA observations, and LIDARs play an important role in the measurement of the aerosol optical depth at any direction. The LIDAR being developed at CEILAP was conceived to operate in harsh environmental conditions during the shifts, and these working conditions may produce misalignments. To minimize these effects, the telescopes comprising the reception unit are controlled by a self-alignment system. This paper describes the self-alignment method and hardware automation.

Pallotta, Juan; Otero, Lidia; Chouza, Fernando; Raul, Delia; Gonzalez, Francisco; Etchegoyen, Alberto; Quel, Eduardo

2013-01-01T23:59:59.000Z

124

Cirrus cloud-temperature interactions over a tropical station, Gadanki from lidar and satellite observations  

SciTech Connect (OSTI)

The cirrus clouds play an important role in the radiation budget of the earth's atmospheric system and are important to characterize their vertical structure and optical properties. LIDAR measurements are obtained from the tropical station Gadanki (13.5{sup 0} N, 79.2{sup 0} E), India, and meteorological indicators derived from Radiosonde data. Most of the cirrus clouds are observed near to the tropopause, which substantiates the strength of the tropical convective processes. The height and temperature dependencies of cloud height, optical depth, and depolarization ratio were investigated. Cirrus observations made using CALIPSO satellite are compared with lidar data for systematic statistical study of cirrus climatology.

S, Motty G, E-mail: mottygs@gmail.com; Satyanarayana, M., E-mail: mottygs@gmail.com; Krishnakumar, V., E-mail: mottygs@gmail.com; Dhaman, Reji k., E-mail: mottygs@gmail.com [Department of Optoelectronics, University of Kerala, Kariavattom, Trivandrum-695 581, Kerala (India)

2014-10-15T23:59:59.000Z

125

Angular output of hollow, metal-lined, waveguide Raman sensors  

SciTech Connect (OSTI)

Hollow, metal-lined waveguides used as gas sensors based on spontaneous Raman scattering are capable of large angular collection. The collection of light from a large solid angle implies the collection of a large number of waveguide modes. An accurate estimation of the propagation losses for these modes is required to predict the total collected Raman power. We report a theory/experimental comparison of the Raman power collected as a function of the solid angle and waveguide length. New theoretical observations are compared with previous theory appropriate only for low-order modes. A cutback experiment is demonstrated to verify the validity of either theory. The angular distribution of Raman light is measured using aluminum and silver-lined waveguides of varying lengths.

Biedrzycki, Stephen; Buric, Michael P.; Falk, Joel; Woodruff, Steven D.

2012-04-20T23:59:59.000Z

126

Detection of Physiologically Relevant Alcohol Concentrations Using Raman Spectroscopy  

E-Print Network [OSTI]

This is the first step in a series of studies to test the feasibility of using Raman Spectroscopy (RS) to non-invasively detect physiologically relevant blood alcohol concentrations. Blood tests, urine tests, and the breathalyzer are currently...

McKay, Joshua L.

2006-08-16T23:59:59.000Z

127

Surface enhanced Raman spectroscopy on a flat graphene surface  

E-Print Network [OSTI]

Surface enhanced Raman spectroscopy (SERS) is an attractive analytical technique, which enables single-molecule sensitive detection and provides its special chemical fingerprints. During the past decades, researchers have ...

Xu, Weigao

128

Quantitative biological Raman spectroscopy for non-invasive blood analysis  

E-Print Network [OSTI]

The long term goal of this project is the measurement of clinically-relevant analytes in the blood tissue matrix of human subjects using near-infrared Raman spectroscopy, with the shorter term research directed towards ...

Shih, Wei-Chuan

2007-01-01T23:59:59.000Z

129

Surface-enhanced Raman scattering (SERS) dosimeter and probe  

DOE Patents [OSTI]

A dosimeter and probe for measuring exposure to chemical and biological compounds is disclosed. The dosimeter or probe includes a collector which may be analyzed by surface-enhanced Raman spectroscopy. The collector comprises a surface-enhanced Raman scattering-active material having a coating applied thereto to improve the adsorption properties of the collector. The collector may also be used in automated sequential devises, in probe array devices.

Vo-Dinh, Tuan (Knoxville, TN)

1995-01-01T23:59:59.000Z

130

Biomass and Bioenergy 31 (2007) 646655 Estimating biomass of individual pine trees using airborne lidar  

E-Print Network [OSTI]

Biomass and Bioenergy 31 (2007) 646­655 Estimating biomass of individual pine trees using airborne biomass and bio-energy feedstocks. The overall goal of this study was to develop a method for assessing aboveground biomass and component biomass for individual trees using airborne lidar data in forest settings

131

Using LIDAR in Highway Rock Cuts Norbert H. Maerz, Ph. D., P. Eng,  

E-Print Network [OSTI]

the data needed to begin the process of modeling the rock raveling process. INTRODUCTION LIDAR damage, injury, and even death. Highways impeded by even small spills of rock material by blasting techniques to facilitate the highway construction. A constant danger to the motoring public

Maerz, Norbert H.

132

Measuring forest structure and biomass in New England forest stands using Echidna ground-based lidar  

E-Print Network [OSTI]

Measuring forest structure and biomass in New England forest stands using Echidna ground Accepted 12 March 2010 Available online 14 May 2011 Keywords: Ground-based lidar Forest structure Biomass biomass with very good accuracy in six New England hardwood and conifer forest stands. Comparing forest

Ni-Meister, Wenge

133

Master Thesis: Dual-Doppler technique applied to scanning lidars for the characterization of  

E-Print Network [OSTI]

of single wind turbines for the validation or tuning of wake models [1]. Recent full-field campaigns showed the opportunity to apply ground based scanning lidar or radar measurements to evaluate the wind field in the wake the correlated wind field. The scope of this master thesis is to study the interaction of wakes on the basis

Peinke, Joachim

134

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model  

E-Print Network [OSTI]

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model 1 dynamics, lIre performed at four diameters behind a 95 kW wind turbine. The wake 111eaeasurement technique allows esti111ation of qUClsiinstantancou~ two dimensional wind fields in an area

135

A geometric framework for channel network extraction from lidar: Nonlinear diffusion and geodesic paths  

E-Print Network [OSTI]

A geometric framework for channel network extraction from lidar: Nonlinear diffusion and geodesic extraction. Following this preprocessing, channels are defined as curves of minimal effort, or geodesics and geodesic paths, J. Geophys. Res., 115, F01002, doi:10.1029/2009JF001254. 1. Introduction [2] The detection

Foufoula-Georgiou, Efi

136

LIDAR OBSERVATIONS AND COMPARISON WITH NUMERICAL SIMULATION OF A LAKE MICHIGAN LAND BREEZE FRONT  

E-Print Network [OSTI]

of the Lake-Induced Convection Experiments (Lake-ICE), on December 21, 1997 the University of Wisconsin VolumeLIDAR OBSERVATIONS AND COMPARISON WITH NUMERICAL SIMULATION OF A LAKE MICHIGAN LAND BREEZE FRONT G circulation over Lake Michigan. Backscatter returns revealed a steady offshore flow extending 1.5 to 4 km

Eloranta, Edwin W.

137

Improved forecasts of extreme weather events by future space borne Doppler wind lidar  

E-Print Network [OSTI]

sensitive areas. To answer these questions simulation experiments with state-of-the-art numerical weather prediction (NWP) models have proved great value to test future meteorological observing systems a prioriImproved forecasts of extreme weather events by future space borne Doppler wind lidar Gert

Marseille, Gert-Jan

138

Topographic accuracy assessment of bare earth lidar-derived unstructured meshes Matthew V. Bilskie  

E-Print Network [OSTI]

: Shallow water equations Unstructured mesh Lidar DEM Storm surge Accuracy a b s t r a c t This study water equations model. A methodology is developed to compute root mean square error (RMSE) and the 95th, urban regions, etc.) and have coarse mesh resolution in areas outside the focus region (e.g. deep water

Central Florida, University of

139

Metal uorescence lidar (light detection and ranging) and the middle atmosphere  

E-Print Network [OSTI]

lidar takes advantage of the naturally occurring sodium atoms between 80 and 110 km above sea level (the though it is exposed to constant solar radiation. The hope of explaining a region strongly coupled as the `-pause' of the layer below them (see ®gure 1). Radiative absorption and emission are dominating eects

140

Lidars in Wind Energy Jakob Mann, Ferhat Bingl, Torben Mikkelsen, Ioannis Antoniou, Mike  

E-Print Network [OSTI]

Lidars in Wind Energy Jakob Mann, Ferhat Bingöl, Torben Mikkelsen, Ioannis Antoniou, Mike Courtney, Gunner Larsen, Ebba Dellwik Juan Jose Trujillo* and Hans E. Jørgensen Wind Energy Department Risø of the presentation · Introduction to wind energy · Accurate profiles of the mean wind speed · Wakes behind turbines

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Remote sensing the wind using Lidars and Sodars Ioannis Antoniou (1)  

E-Print Network [OSTI]

of the met masts increases rapidly with height. The evolution of new multi-MW wind turbines has resulted), as met towers increase in height, increases rapidly. The second reason is the measurement of the windRemote sensing the wind using Lidars and Sodars Ioannis Antoniou (1) , Mike Courtney(1) , Hans E

142

Impact Assessment of Simulated Doppler Wind Lidars with a Multivariate Variational Assimilation in the Tropics  

E-Print Network [OSTI]

forecast errors of the European Centre for Medium-Range Weather Forecasts (ECMWF) model. Tropical mass­windImpact Assessment of Simulated Doppler Wind Lidars with a Multivariate Variational Assimilation, De Bilt, Netherlands CHRISTOPHE ACCADIA AND PETER SCHL�SSEL European Organisation

Stoffelen, Ad

143

Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration  

SciTech Connect (OSTI)

New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

Rodney Frehlich

2012-10-30T23:59:59.000Z

144

Master thesis: "Validation of wake-simulation models based on long-range lidar measurements."  

E-Print Network [OSTI]

REpower 6M wind turbines with rotor blades of different designs installed in the Ellhöft/Westre wind farm developed by the wind turbine manufacturer. Work plan 2011 2012 Task 11 12 01 02 03 04 05 06 07 08 09 10 Figure 1: Simulation of lidar measurements in the wake of a wind turbine using a LES generated wind field

Peinke, Joachim

145

Nanopillars array for surface enhanced Raman scattering  

SciTech Connect (OSTI)

The authors present a new class of surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. Two types of nanopillars within this class are discussed: vertical pillars and tapered pillars. For the vertical pillars, the gap between each pair of nanopillars is small enough (< 50 nm) such that highly confined plasmonic cavity resonances are supported between the pillars when light is incident upon them, and the anti-nodes of these resonances act as three-dimensional hotspots for SERS. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of 1,2 bis-(4-pyridyl)-ethylene (BPE), benzenethiol (BT) monolayer and toluene vapor. The results show that SERS enhancement factor of over 0.5 x 10{sup 9} can be achieved, and BPE can be detected down to femto-molar concentration level. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors such as volatile organic compounds.

S.P. Chang, A; Bora, M; Nguyen, H T; Behymer, E M; Larson, C C; Britten, J A; Carter, J C; Bond, T C

2011-04-14T23:59:59.000Z

146

Detection and Quantitative Analysis of Chemical Species in Hanford Tank Materials Using Raman Spectroscopy Technology: FY94Florida State University Raman Spectroscopy Report  

SciTech Connect (OSTI)

This report provides a summary of work completed in FY-94 by FSU to develop and investigate the feasibility of using Raman spectroscopy with Hanford tank waste materials. Raman performance impacts from sample morphology, including the effects of absorption, particle size, density, color and refractive index, are discussed. An algorithm for relative species concentration measurement from Raman data is presented. An Algorithm for applying Raman to tank waste core screening is presented and discussed. A library of absorption and Raman spectra are presented that support this work.

Reich, F.R.

1997-08-11T23:59:59.000Z

147

Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data  

SciTech Connect (OSTI)

Detailed hydrographic feature extraction from high-resolution light detection and ranging (LiDAR) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from LiDAR-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates a new method of delineating a stream directly from LiDAR point clouds, without the intermediate step of deriving a DEM. Direct use of LiDAR point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the LiDAR data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.

Danny L. Anderson

2012-05-01T23:59:59.000Z

148

Raman Spectroscopy of Carbon Dust Samples from NSTX  

SciTech Connect (OSTI)

The Raman spectrum of dust particles exposed to the NSTX plasma is different from the spectrum of unexposed particles scraped from an unused graphite tile. For the unexposed particles, the high energy G-mode peak (Raman shift ~1580 cm-1) is much stronger than the defect-induced D-mode peak (Raman shift ~ 1350 cm-1), a pattern that is consistent with Raman spectrum for commercial graphite materials. For dust particles exposed to the plasma, the ratio of G-mode to D-mode peaks is lower and becomes even less than 1. The Raman measurements indicate that the production of carbon dust particles in NSTX involves modifications of the physical and chemical structure of the original graphite material. These modifications are shown to be similar to those measured for carbon deposits from atmospheric pressure helium arc discharge with an ablating anode electrode made from a graphite tile material. We also demonstrate experimentally that heating to 2000-2700 K alone can not explain the observed structural modifications indicating that they must be due to higher temperatures needed for graphite vaporization, which is followed either by condensation or some plasma-induced processes leading to the formation of more disordered forms of carbon material than the original graphite.

Y. Raitses, C.H. Skinner, F. Jiang and T.S. Duffy

2008-02-21T23:59:59.000Z

149

Estimating forest structural characteristics with airborne lidar scanning and a near-real time profiling laser systems  

E-Print Network [OSTI]

LiDAR (Light Detection and Ranging) directly measures canopy vertical structures, and provides an effective remote sensing solution to accurate and spatiallyexplicit mapping of forest characteristics, such as canopy height and Leaf Area Index...

Zhao, Kaiguang

2009-05-15T23:59:59.000Z

150

Method to determine and adjust the alignment of the transmitter and receiver fields of view of a LIDAR system  

DOE Patents [OSTI]

A method to determine the alignment of the transmitter and receiver fields of view of a light detection and ranging (LIDAR) system. This method can be employed to determine the far-field intensity distribution of the transmitter beam, as well as the variations in transmitted laser beam pointing as a function of time, temperature, or other environmental variables that may affect the co-alignment of the LIDAR system components. In order to achieve proper alignment of the transmitter and receiver optical systems when a LIDAR system is being used in the field, this method employs a laser-beam-position-sensing detector as an integral part of the receiver optics of the LIDAR system.

Schmitt, Randal L. (Tijeras, NM); Henson, Tammy D. (Albuquerque, NM); Krumel, Leslie J. (Cedar Crest, NM); Hargis, Jr., Philip J. (Albuquerque, NM)

2006-06-20T23:59:59.000Z

151

Field Test Results of Using a Nacelle-Mounted Lidar for Improving Wind Energy Capture by Reducing Yaw Misalignment (Presentation)  

SciTech Connect (OSTI)

Presented at the Nordic Wind Power Conference on November 5, 2014. This presentation describes field-test campaigns performed at the National Wind Technology Center in which lidar technology was used to improve the yaw alignment of the Controls Advanced Research Turbine (CART) 2 and CART3 wind turbines. The campaigns demonstrated that whether by learning a correction function to the nacelle vane, or by controlling yaw directly with the lidar signal, a significant improvement in power capture was demonstrated.

Fleming, P.; Scholbrock, A.; Wright, A.

2014-11-01T23:59:59.000Z

152

Noise figure and photon statistics in coherent anti-Stokes Raman scattering  

E-Print Network [OSTI]

). 11. J. Perina, "Photon statistics in Raman scattering with frequency mismatch," Optica Acta 28, 1529 (1981). 12. J. Perina, "Photon statistics in Raman scattering of intense coherent light," Optica Acta 28

Jalali. Bahram

153

The application of surface-enhanced Raman spectroscopy for the detection of excitatory amino acids  

E-Print Network [OSTI]

enhanced Raman spectroscopy (SERS) on aqueous silver colloids. This study examines methods to monitor the colloidal reactions for the calibration of the enhancement observed. Thirty second Raman spectral scans were taken utilizing a 50 mW argon laser...

O'Neal, Dennis Patrick Doucet

1999-01-01T23:59:59.000Z

154

Coherent anti-Stokes Raman scattering (CARS) optimized by exploiting optical interference  

E-Print Network [OSTI]

The purpose of this work is to study the interference between the coherent nonresonant four-wave-mixing (FWM) background and the Raman-resonant signal in the coherent anti-Stokes Raman spectroscopy (CARS). The nonresonant background is usually...

Wang, Xi

2012-07-16T23:59:59.000Z

155

Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye...  

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

Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye-Sensitized TiO2 Nanoparticles. Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye-Sensitized TiO2...

156

G? band in double- and triple-walled carbon nanotubes: A Raman study  

E-Print Network [OSTI]

Double- and triple-walled carbon nanotubes are studied in detail by laser energy-dependent Raman spectroscopy in order to get a deeper understanding about the second-order G[superscript '] band Raman process, general ...

Hirschmann, Thomas Ch.

157

Surface-Enhanced Raman Scattering Study on Graphene-Coated Metallic Nanostructure Substrates  

E-Print Network [OSTI]

#12;Surface-Enhanced Raman Scattering Study on Graphene-Coated Metallic Nanostructure Substrates University, University Park, Pennsylvania 16802, United States *S Supporting Information ABSTRACT: Graphene, we combine graphene with conventional metallic surface- enhanced Raman scattering (SERS) substrates

158

Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto  

DOE Patents [OSTI]

Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

2014-07-22T23:59:59.000Z

159

E-Print Network 3.0 - auger resonant raman Sample Search Results  

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

Summary: Gas hydrate measurements at Hydrate Ridge using Raman spectroscopy K.C. Hester a , R.M. Dunk b , S... for the first time using a seagoing Raman spectrometer at...

160

Cone penetrometer fiber optic raman spectroscopy probe assembly  

DOE Patents [OSTI]

A chemically and mechanically robust optical Raman spectroscopy probe assembly that can be incorporated in a cone penetrometer (CPT) for subsurface deployment. This assembly consists of an optical Raman probe and a penetrometer compatible optical probe housing. The probe is intended for in-situ chemical analysis of chemical constituents in the surrounding environment. The probe is optically linked via fiber optics to the light source and the detection system at the surface. A built-in broadband light source provides a strobe method for direct measurement of sample optical density. A mechanically stable sapphire window is sealed directly into the side-wall of the housing using a metallic, chemically resistant, hermetic seal design. This window permits transmission of the interrogation light beam and the resultant signal. The spectroscopy probe assembly is capable of accepting Raman, Laser induced Fluorescence, reflectance, and other optical probes with collimated output for CPT deployment.

Kyle, Kevin R. (Brentwood, CA); Brown, Steven B. (Livermore, CA)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

UV resonance Raman analysis of trishomocubane and diamondoid dimers  

SciTech Connect (OSTI)

We present resonance Raman measurements of crystalline trishomocubane and diamantane dimers containing a C=C double bond. Raman spectra were recorded with excitation energies between 2.33 eV and 5.42 eV. The strongest enhancement is observed for the C=C stretch vibration and a bending mode involving the two carbon atoms of the C=C bond, corresponding to the B{sub 2g} wagging mode of ethylene. This is associated with the localization of the ?-HOMO and LUMO and the elongation of the C=C bond length and a pyramidalization of the two sp{sup 2}-hybridized carbon atoms at the optical excitation. The observed Raman resonance energies of the trishomocubane and diamantane dimers are significantly lower than the HOMO-LUMO gaps of the corresponding unmodified diamondoids.

Meinke, Reinhard, E-mail: rene@physik.tu-berlin.de; Thomsen, Christian; Maultzsch, Janina [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany)] [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany); Richter, Robert; Merli, Andrea [Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany)] [Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany); Fokin, Andrey A. [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany) [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany); Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev (Ukraine); Koso, Tetyana V.; Schreiner, Peter R. [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany)] [Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, D-35392 Giessen (Germany); Rodionov, Vladimir N. [Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev (Ukraine)] [Department of Organic Chemistry, Kiev Polytechnic Institute, pr. Pobedy 37, 03056 Kiev (Ukraine)

2014-01-21T23:59:59.000Z

162

Standoff ultraviolet raman scattering detection of trace levels of explosives.  

SciTech Connect (OSTI)

Ultraviolet (UV) Raman scattering with a 244-nm laser is evaluated for standoff detection of explosive compounds. The measured Raman scattering albedo is incorporated into a performance model that focused on standoff detection of trace levels of explosives. This model shows that detection at {approx}100 m would likely require tens of seconds, discouraging application at such ranges, and prohibiting search-mode detection, while leaving open the possibility of short-range point-and-stare detection. UV Raman spectra are also acquired for a number of anticipated background surfaces: tile, concrete, aluminum, cloth, and two different car paints (black and silver). While these spectra contained features in the same spectral range as those for TNT, we do not observe any spectra similar to that of TNT.

Kulp, Thomas J.; Bisson, Scott E.; Reichardt, Thomas A.

2011-10-01T23:59:59.000Z

163

HiRes camera and LIDAR ranging system for the Clementine mission  

SciTech Connect (OSTI)

Lawrence Livermore National Laboratory developed a space-qualified High Resolution (HiRes) imaging LIDAR (Light Detection And Ranging) system for use on the DoD Clementine mission. The Clementine mission provided more than 1.7 million images of the moon, earth, and stars, including the first ever complete systematic surface mapping of the moon from the ultra-violet to near-infrared spectral regions. This article describes the Clementine HiRes/LIDAR system, discusses design goals and preliminary estimates of on-orbit performance, and summarizes lessons learned in building and using the sensor. The LIDAR receiver system consists of a High Resolution (HiRes) imaging channel which incorporates an intensified multi-spectral visible camera combined with a Laser ranging channel which uses an avalanche photo-diode for laser pulse detection and timing. The receiver was bore sighted to a light-weight McDonnell-Douglas diode-pumped ND:YAG laser transmitter that emmitted 1.06 {micro}m wavelength pulses of 200 mJ/pulse and 10 ns pulse-width, The LIDAR receiver uses a common F/9.5 Cassegrain telescope assembly. The optical path of the telescope is split using a color-separating beamsplitter. The imaging channel incorporates a filter wheel assembly which spectrally selects the light which is imaged onto a custom 12 mm gated image intensifier fiber-optically-coupled into a 384 x 276 pixel frame transfer CCD FPA. The image intensifier was spectrally sensitive over the 0.4 to 0.8 {micro}m wavelength region. The six-position filter wheel contained 4 narrow spectral filters, one broadband and one blocking filter. At periselene (400 km) the HiRes/LIDAR imaged a 2.8 km swath width at 20-meter resolution. The LIDAR function detected differential signal return with a 40-meter range accuracy, with a maximum range capability of 640 km, limited by the bit counter in the range return counting clock.

Ledebuhr, A.G.; Kordas, J.F.; Lewis, I.T. [and others

1995-04-01T23:59:59.000Z

164

Outline Phonon spectra of graphene Raman spectra of graphene Crystal lattice dynamics  

E-Print Network [OSTI]

Seminar Heng Wang University of Konstanz July 11, 2013 Heng Wang University of Konstanz () Crystal lattice Raman spectra of graphene What is Raman scattering Applications of Raman spectroscopy of graphene Heng (2013). Heng Wang University of Konstanz () Crystal lattice dynamics July 11, 2013 3 / 19 #12;Outline

165

Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background Behavior  

E-Print Network [OSTI]

ARTICLE Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella while acquiring Raman signals from the algae. The time dependence of fluorescence background is char

166

Raman scattering in carbon nanotubes revisited J. Maultzsch, S. Reich, and C. Thomsen  

E-Print Network [OSTI]

of whether the high-energy Raman spectrum in carbon nanotubes is also dominated by processes that allow for understanding the high-energy modes in carbon nanotubes attribute the ob- served Raman peaks to -pointRaman scattering in carbon nanotubes revisited J. Maultzsch, S. Reich, and C. Thomsen Institut fu

Nabben, Reinhard

167

Variable temperature Raman microscopy as a nanometrology tool for graphene layers and graphene-based devices  

E-Print Network [OSTI]

Variable temperature Raman microscopy as a nanometrology tool for graphene layers and graphene; accepted 24 July 2007; published online 15 August 2007 Raman microscopy of graphene was carried out over-band frequencies extracted from Raman spectra of the single-layer graphene are - 1.6±0.2 10-2 cm-1 /K and - 3

168

OAK 270 - The use of Lidar/radiometer (LIRAD) in the ARM program to obtain optical properties and microphysics of high and midlevel clouds  

SciTech Connect (OSTI)

OAK 270 - The use of Lidar/Radiometer (LIRAD) in the ARM program to obtain optical properties and microphysics of high and midlevel clouds

C.M.R. Platt; R.T. Austin; S.A. Young; and G.L. Stephens

2002-12-13T23:59:59.000Z

169

Stimulated Raman scattering in an ethanol core microstructured optical fiber  

E-Print Network [OSTI]

Delaye, Anne Rouvie, Jordi Chinaud, Robert Frey, Gérald Roosen Laboratoire Charles Fabry de l'Institut d" Phys. Rev. Lett. 9, 455 (1962) 2. Y.R. Shen "The principles of nonlinear optics" (John Wiley and Sons, New York, 1994). 4. R.Frey, F. Pradère "Powerful tunable infrared generation by stimulated Raman

Paris-Sud XI, Université de

170

CLIENT : Indian Academy of Sciences C. V. RAMAN AVENUE,  

E-Print Network [OSTI]

1 CLIENT : Indian Academy of Sciences C. V. RAMAN AVENUE, SADASHIVNAGAR, BANGALORE ­ 560080 TENDER FOR : PROPOSED HOSTEL BLOCK AT INDIAN ACADEMY OF SCIENCES, FELLOWS RESIDENCY NEXT TO ISRO QUARTERS, JALAHALLI AND PLUMBING WORKS : 136-138 #12;3 INDIAN ACADEMY OF SCIENCES BANGALORE ­ 560080 NOTICE INVITING TENDER SEALED

Joshi, Yogesh Moreshwar

171

Electrochemical and Raman measurements on single-walled carbon nanotubes  

E-Print Network [OSTI]

Electrochemical and Raman measurements on single-walled carbon nanotubes M. Stoll a,*, P performed on a carbon nanotube mat as a working electrode using different salt solutions. The gravimetric capacitance of the nanotube material was estimated and its effective surface area was de- termined in a purely

Nabben, Reinhard

172

Raman Scattering in Carbon Nanotubes Christian Thomsen1  

E-Print Network [OSTI]

energy [4]. Theoretically, the electronic dispersion of nanotubes may be described by an- alyticRaman Scattering in Carbon Nanotubes Christian Thomsen1 and Stephanie Reich2 1 Institut f¨ur Festk of single-walled carbon nanotubes reflect the electron and phonon confinement as well as the cylindrical

Nabben, Reinhard

173

Probing the Intrinsic Properties of Exfoliated Graphene: Raman  

E-Print Network [OSTI]

Probing the Intrinsic Properties of Exfoliated Graphene: Raman Spectroscopy of Free-standing graphene monolayers prepared by mechanical exfoliation of graphite are investigated. The graphene,7 or to solubilize macroscopic quantities of graphene,8 mechanical exfoliation of graphite9 currently remains

Heinz, Tony F.

174

Raman Amplification of Laser Pulses in Microcapillary Plasmas  

E-Print Network [OSTI]

of overcoming the power limit of current chirped-pulse-amplification (CPA) CP641, X-Ray Lasers 2002: 8th International Conference on X-Ray Lasers, edited by J. J. Rocca et al. > 2002American Institute of Physics 0 of the optics. Such Raman amplifiers can be useful to produce ultra-intense laser pulses for pumping soft x-ray

175

hal00276997, Raman spectra of misoriented bilayer graphene  

E-Print Network [OSTI]

hal­00276997, version 1 ­ 5 May 2008 Raman spectra of misoriented bilayer graphene P. Poncharal 1 spectra from single layer graphene with a bilayer in which the two layers are arbitrarily misoriented to the similarity of the electronic structures of single layer graphene and misoriented bilayer graphene. Another

Paris-Sud XI, Université de

176

Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy  

E-Print Network [OSTI]

Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy Department of Microbial and Environmental Microfluidics Group (http://web.mit.edu/romanstocker) Department of Civil & Environmental (junior or senior) with strong expertise in microfluidics and an interest in applying it to microbial

Horn, Matthias

177

Technical Notes UV Resonance Raman Spectroscopic Detection of  

E-Print Network [OSTI]

- in wastewater for the real-time control of water treatment plants. The reliability and performance of biological nutrient removal (BNR) wastewater treatment plants (WWTPs) can be enhanced by the ability to monitor the utility of UV resonance Raman3-8 spectroscopy to monitor nitrate and nitrite in wastewater treatment

Asher, Sanford A.

178

Raman spectroscopic studies of chemical speciation in calcium chloride melts  

SciTech Connect (OSTI)

Raman spectroscopy was applied to CaCl2 melts at 900 degrees C under both non-electrolyzed and electrolyzed conditions. The later used titania cathodes supplied by TIMET, Inc. and graphite anodes. Use of pulse-gating to collect the Raman spectra successfully eliminated any interference from black-body radiation and other stray light. The spectrum of molten CaCl2 exhibited no distinct, resolvable bands that could be correlated with a calcium chloride complex similar to MgCl42- in MgCl2 melts. Rather, the low frequency region of the spectrum was dominated by a broad “tail” arising from collective oscillations of both charge and mass in the molten salt “network.” Additions of both CaO and Ca at concentrations of a percent or two resulted in no new features in the spectra. Addition of CO2, both chemically and via electrolysis at concentrations dictated by stability and solubility at 900 degrees C and 1 bar pressure, also produced no new bands that could be correlated with either dissolved CO2 or the carbonate ion. These results indicated that Raman spectroscopy, at least under the conditions evaluated in the research, was not well suited for following the reactions and coordination chemistry of calcium ions, nor species such as dissolved metallic Ca and CO2 that are suspected to impact current efficiency in titanium electrolysis cells using molten CaCl2. Raman spectra of TIMET titania electrodes were successfully obtained as a function of temperature up to 900 degrees C, both in air and in-situ in CaCl2 melts. However, spectra of these electrodes could only be obtained when the material was in the unreduced state. When reduced, either with hydrogen or within an electrolysis cell, the resulting electrodes exhibited no measurable Raman bands under the conditions used in this work.

Windisch, Charles F.; Lavender, Curt A.

2005-02-01T23:59:59.000Z

179

Graphene as a Substrate To Suppress Fluorescence in Resonance Raman Spectroscopy  

E-Print Network [OSTI]

Resonance Raman spectroscopy (RRS), which can enhance Raman signal by 107 times than normal Raman spectroscopy, is a powerful approach to characterize structures of chemicals (especially biomolecules) at low concentrations.1-4 However, fluorescence (FL) background is a major obstacle in RRS because the FL cross section (?10-16 cm2) is much larger than the RRS cross section (?10-22 cm2).3 Several approaches, such as ultraviolet RRS (UV-RRS),1 time-resolved Raman detection,5,6 femtosecond broadband stimu-lated Raman spectroscopy (FSRS),7 and coherent anti-Stokes Raman spectroscopy (CARS),8 have been used to suppress or reject FL background in RRS. However, these approaches need expensive and complex equipments and have other limitations, such as sample degradation in UV-RRS. Surface-enhanced Raman spectroscopy (SERS) is another powerful approach to characterize structures of chemicals at extremely low concentrations or even at the single

Liming Xie; Xi Ling; Yuan Fang; Jin Zhang; Zhongfan Liu

2009-01-01T23:59:59.000Z

180

Meas. Sci. Technol. 10 (1999) 11781184. Printed in the UK PII: S0957-0233(99)06575-3 Submarine lidar for seafloor  

E-Print Network [OSTI]

for the detection of dissolved and sunken pollutants. One of these instruments is the submarine lidar, combining: fluorescence lidar, range-gating video, seafloor monitoring 1. Submarine sensor network for pollution of Oldenburg, Laser Remote Sensing Group), · an acoustic sensor for measuring the acoustic impedance

Oldenburg, Carl von Ossietzky Universität

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Surface-Enhanced Raman Optical Data Storage system  

DOE Patents [OSTI]

A method and apparatus for a Surface-Enhanced Raman Optical Data Storage (SERODS) System are disclosed. A medium which exhibits the Surface Enhanced Raman Scattering (SERS) phenomenon has data written onto its surface of microenvironment by means of a write-on procedure which disturbs the surface or microenvironment of the medium and results in the medium having a changed SERS emission when excited. The write-on procedure is controlled by a signal that corresponds to the data to be stored so that the disturbed regions on the storage device (e.g., disk) represent the data. After the data is written onto the storage device it is read by exciting the surface of the storage device with an appropriate radiation source and detecting changes in the SERS emission to produce a detection signal. The data is then reproduced from the detection signal. 5 figures.

Vo-Dinh, T.

1991-03-12T23:59:59.000Z

182

Surface-enhanced raman optical data storage system  

DOE Patents [OSTI]

A method and apparatus for a Surface-Enhanced Raman Optical Data Storage (SERODS) System is disclosed. A medium which exhibits the Surface Enhanced Raman Scattering (SERS) phenomenon has data written onto its surface of microenvironment by means of a write-on procedure which disturbs the surface or microenvironment of the medium and results in the medium having a changed SERS emission when excited. The write-on procedure is controlled by a signal that corresponds to the data to be stored so that the disturbed regions on the storage device (e.g., disk) represent the data. After the data is written onto the storage device it is read by exciting the surface of the storage device with an appropriate radiation source and detecting changes in the SERS emission to produce a detection signal. The data is then reproduced from the detection signal.

Vo-Dinh, Tuan (Knoxville, TN)

1991-01-01T23:59:59.000Z

183

Ultrafast stimulated Raman parallel adiabatic passage by shaped pulses  

E-Print Network [OSTI]

We present a general and versatile technique of population transfer based on {\\it parallel adiabatic passage} by femtosecond shaped pulses. Their amplitude and phase are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times. We show that this technique allows the robust adiabatic population transfer in a Raman system with the total pulse area as low as 3 $\\pi$, corresponding to a fluence of one order of magnitude below the conventional stimulated Raman adiabatic passage process. This process of short duration, typically pico- and subpicosecond, is easily implementable with the modern pulse shaper technology and opens the possibility of ultrafast robust population transfer with interesting applications in quantum information processing.

G. Dridi; S. Guerin; V. Hakobyan; H. R. Jauslin; H. Eleuch

2009-10-06T23:59:59.000Z

184

Raman scheme for adjustable-bandwidth quantum memory  

SciTech Connect (OSTI)

We propose a scenario of quantum memory for light based on Raman scattering. The storage medium is a vapor and the different spectral components of the input pulse are stored in different atomic velocity classes. One uses appropriate pulses to reverse the resulting Doppler phase shift and to regenerate the input pulse, without distortion, in the backward direction. The different stages of the protocol are detailed and the recovery efficiency is calculated in the semiclassical picture. Since the memory bandwidth is determined by the Raman transition Doppler width, it can be adjusted by changing the angle between the input pulse wave vector and the control beams. The optical depth also depends on the beam angle. As a consequence the available optical depth can be optimized depending on the needed bandwidth. The predicted recovery efficiency is close to 100% for large optical depth.

Le Goueet, J.-L.; Berman, P. R. [Laboratoire Aime Cotton, CNRS UPR3321, Universite Paris Sud, Batiment 505, Campus Universitaire, 91405 Orsay (France); Department of Physics and Michigan Center for Theoretical Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)

2009-07-15T23:59:59.000Z

185

X-ray Raman scattering study of aligned polyfluorene  

E-Print Network [OSTI]

We present a non-resonant inelastic x-ray scattering study at the carbon K-edge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that the x-ray Raman scattering technique can be used as a practical alternative to x-ray absorption measurements. We demonstrate that this novel method can be applied to studies on aligned $\\pi$-conjugated polymers complementing diffraction and optical studies. Combining the experimental data and a very recently proposed theoretical scheme we demonstrate a unique property of x-ray Raman scattering by performing the symmetry decomposition on the density of unoccupied electronic states into $s$- and $p$-type symmetry contributions.

S. Galambosi; M. Knaapila; J. A. Soininen; K. Nyg\\aard; S. Huotari; F. Galbrecht; U. Scherf; A. P. Monkman; K. Hämäläinen

2006-08-29T23:59:59.000Z

186

Multi mode nano scale Raman echo quantum memory  

E-Print Network [OSTI]

Low loss magnetic surface plasmon polariton (SPP) modes characterized by enhanced electrical field component and subwavelength confinement on the dielectric and negative-index metamaterial interface are presented. We demonstrate a possibility of storage and perfect retrieval of the low loss magnetic SPP fields by using a photon echo quantum memory on Raman atomic transition. We describe specific properties of the proposed technique which opens a possibility for efficient nano scale multi-mode quantum memory.

S. A. Moiseev; E. S. Moiseev

2010-01-31T23:59:59.000Z

187

The infrared and Raman spectra of N-alkyl ethylenimines  

E-Print Network [OSTI]

and Assi nments. . . . . . . . . . . . . . . , 5 A, Structural Considerations. . . . ~ . . . , . . . , 5 B, Assi"na ent of Spectra. . . . . . , . . . . . . . . . . 9 1, Yethod, 9 2. N-Yethyl Ethylenimine, . . . . , . . . . . . . 10 3. N-Ethyl... the Or ientation of the Principal Axes. Page 2. The Infrared Spectrum of I!-Yythyl Ethy- lenimine from 4000 to 50 cm . . . . . . . , . . . . 11 3. The Raman Spectrum of !! i~'. ethyl Ethylenimine. 13 4. The Infrared Spectrum of N-Ethyl Ethy- lenimine from...

Ashby, Theodore Leroy

1968-01-01T23:59:59.000Z

188

Raman fiber optic probe assembly for use in hostile environments  

DOE Patents [OSTI]

This invention provides a device for Raman spectroscopic measurement of composition and concentrations in a hostile environment by the use of a first fiber optic as a means of directing high intensity monochromatic light from a laser to the hostile environment and a second fiber optic to receive the lower intensity scattered light for transmittal to a monochromator for analysis. To avoid damage to the fiber optics, they are protected from the hostile environment. A preferred embodiment of the Raman fiber optic probe is able to obtain Raman spectra of corrosive gases and solutions at temperatures up to 600.degree. F. and pressures up to 2000 psi. The incident exciting fiber optic cable makes an angle of substantially 90.degree. with the collecting fiber optic cable. This 90.degree. geometry minimizes the Rayleigh scattering signal picked up by the collecting fiber, because the intensity of Rayleigh scattering is lowest in the direction perpendicular to the beam path of the exciting light and therefore a 90.degree. scattering geometry optimizes the signal to noise ratio.

Schmucker, John E. (Hurt, VA); Falk, Jon C. (Pittsburgh, PA); Archer, William B. (Bethel Park, PA); Blasi, Raymond J. (Harrison City, PA)

2000-01-01T23:59:59.000Z

189

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

SciTech Connect (OSTI)

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

Hostetler, Chris; Ferrare, Richard

2013-02-14T23:59:59.000Z

190

ARM - Evaluation Product - MicroPulse LIDAR Cloud Optical Depth (MPLCOD)  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcal Documentation(AVIRIS) ProductsAirborne Visible/InfraredProductsMicroPulse LIDAR Cloud Optical Depth (MPLCOD)

191

AFM CHARACTERIZATION OF RAMAN LASER INDUCED DAMAGE ON CDZNTECRYSTAL SURFACES  

SciTech Connect (OSTI)

High quality CdZnTe (or CZT) crystals have the potential for use in room temperature gamma-ray and X-ray spectrometers. Over the last decade, the methods for growing high quality CZT have improved the quality of the produced crystals however there are material features that can influence the performance of these materials as radiation detectors. The presence of structural heterogeneities within the crystals, such as twinning, pipes, grain boundaries (polycrystallinity), and secondary phases (SPs) can have an impact on the detector performance. There is considerable need for reliable and reproducible characterization methods for the measurement of crystal quality. With improvements in material characterization and synthesis, these crystals may become suitable for widespread use in gamma radiation detection. Characterization techniques currently utilized to test for quality and/or to predict performance of the crystal as a gamma-ray detector include infrared (IR) transmission imaging, synchrotron X-ray topography, photoluminescence spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Raman spectroscopy. In some cases, damage caused by characterization methods can have deleterious effects on the crystal performance. The availability of non-destructive analysis techniques is essential to validate a crystal's quality and its ability to be used for either qualitative or quantitative gamma-ray or X-ray detection. The work presented herein discusses the damage that occurs during characterization of the CZT surface by a laser during Raman spectroscopy, even at minimal laser powers. Previous Raman studies have shown that the localized annealing from tightly focused, low powered lasers results in areas of higher Te concentration on the CZT surface. This type of laser damage on the surface resulted in decreased detector performance which was most likely due to increased leakage current caused by areas of higher Te concentration. In this study, AFM was used to characterize the extent of damage to the CZT crystal surface following exposure to a Raman laser. AFM data reveal localized surface damage and increased conductivity in the areas exposed to the Raman laser beam.

Teague, L.; Duff, M.

2008-10-07T23:59:59.000Z

192

E-Print Network 3.0 - absorption phonon raman Sample Search Results  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: absorption phonon raman Page: << < 1 2 3 4 5 > >> 1 SELECTION RULES FOR SECOND ORDER INFRARED...

193

Modeling LIDAR Detection of Biological Aerosols to Determine Optimum Implementation Strategy  

SciTech Connect (OSTI)

This report summarizes work performed for a larger multi-laboratory project named the Background Interferent Measurement and Standards project. While originally tasked to develop algorithms to optimize biological warfare agent detection using UV fluorescence LIDAR, the current uncertainties in the reported fluorescence profiles and cross sections the development of any meaningful models. It was decided that a better approach would be to model the wavelength-dependent elastic backscattering from a number of ambient background aerosol types, and compare this with that generated from representative sporulated and vegetative bacterial systems. Calculations in this report show that a 266, 355, 532 and 1064 nm elastic backscatter LIDAR experiment will allow an operator to immediately recognize when sulfate, VOC-based or road dust (silicate) aerosols are approaching, independent of humidity changes. It will be more difficult to distinguish soot aerosols from biological aerosols, or vegetative bacteria from sporulated bacteria. In these latter cases, the elastic scattering data will most likely have to be combined with UV fluorescence data to enable a more robust categorization.

Sheen, David M.; Aker, Pam M.

2007-09-19T23:59:59.000Z

194

Lidar Investigation of Tropical Nocturnal Boundary Layer Aerosols and Cloud Macrophysics  

SciTech Connect (OSTI)

Observational evidence of two-way association between nocturnal boundary layer aerosols and cloud macrophysical properties under different meteorological conditions is reported in this paper. The study has been conducted during 2008-09 employing a high space-time resolution polarimetric micro-pulse lidar over a tropical urban station in India. Firstly, the study highlights the crucial role of boundary layer aerosols and background meteorology on the formation and structure of low-level stratiform clouds in the backdrop of different atmospheric stability conditions. Turbulent mixing induced by the wind shear at the station, which is associated with a complex terrain, is found to play a pivotal role in the formation and structural evolution of nocturnal boundary layer clouds. Secondly, it is shown that the trapping of energy in the form of outgoing terrestrial radiation by the overlying low-level clouds can enhance the aerosol mixing height associated with the nocturnal boundary layer. To substantiate this, the long-wave heating associated with cloud capping has been quantitatively estimated in an indirect way by employing an Advanced Research Weather Research and Forecasting (WRF-ARW) model version 2.2 developed by National Center for Atmospheric Research (NCAR), Colorado, USA, and supplementary data sets; and differentiated against other heating mechanisms. The present investigation as well establishes the potential of lidar remote-sensing technique in exploring some of the intriguing aspects of the cloud-environment relationship.

Manoj, M. G.; Devara, PC S.; Taraphdar, Sourav

2013-10-01T23:59:59.000Z

195

Field Test Results from Lidar Measured Yaw Control for Improved Yaw Alignment with the NREL Controls Advanced Research Turbine: Preprint  

SciTech Connect (OSTI)

This paper describes field tests of a light detection and ranging (lidar) device placed forward looking on the nacelle of a wind turbine and used as a wind direction measurement to directly control the yaw position of a wind turbine. Conventionally, a wind turbine controls its yaw direction using a nacelle-mounted wind vane. If there is a bias in the measurement from the nacelle-mounted wind vane, a reduction in power production will be observed. This bias could be caused by a number of issues such as: poor calibration, electromagnetic interference, rotor wake, or other effects. With a lidar mounted on the nacelle, a measurement of the wind could be made upstream of the wind turbine where the wind is not being influenced by the rotor's wake or induction zone. Field tests were conducted with the lidar measured yaw system and the nacelle wind vane measured yaw system. Results show that a lidar can be used to effectively measure the yaw error of the wind turbine, and for this experiment, they also showed an improvement in power capture because of reduced yaw misalignment when compared to the nacelle wind vane measured yaw system.

Scholbrock, A.; Fleming, P.; Wright, A.; Slinger, C.; Medley, J.; Harris, M.

2014-12-01T23:59:59.000Z

196

SIMULTANEOUS AND COMMON-VOLUME LIDAR OBSERVATIONS OF THE MESOSPHERIC FE AND NA LAYERS AT BOULDER (40N, 105W)  

E-Print Network [OSTI]

inputs can reproduce some large-scale characteristics but are challenged in simulating small- scale the general structures more precisely as well as simulating the challenging small scale features. In Aug. The Fe Boltzmann temperature lidar was under upgrading and validating at Boulder before its deployment

Chu, Xinzhao

197

3D Temperature Measurement in IC Chips using Confocal Raman Spectroscopy Javad Shabani, Xi Wang, and Ali Shakouri  

E-Print Network [OSTI]

. The feasibility of using Raman spectroscopy for remote temperature measurement in depth was investigated value where the surface temperature starts to rise due to heating by incident light. #12;Raman

198

Cloud Effects on Radiative Heating Rate Profiles over Darwin using ARM and A-train Radar/Lidar Observations  

SciTech Connect (OSTI)

Observations of clouds from the ground-based U.S. Department of Energy Atmospheric Radiation Measurement program (ARM) and satellite-based A-train are used to compute cloud radiative forcing profiles over the ARM Darwin, Australia site. Cloud properties are obtained from both radar (the ARM Millimeter Cloud Radar (MMCR) and the CloudSat satellite in the A-train) and lidar (the ARM Micropulse lidar (MPL) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite in the A-train) observations. Cloud microphysical properties are taken from combined radar and lidar retrievals for ice clouds and radar only or lidar only retrievals for liquid clouds. Large, statistically significant differences of up to 1.43 K/day exist between the mean ARM and A-train net cloud radiative forcing profiles. The majority of the difference in cloud radiative forcing profiles is shown to be due to a large difference in the cloud fraction above 12 km. Above this altitude the A-train cloud fraction is significantly larger because more clouds are detected by CALIPSO than by the ground-based MPL. It is shown that the MPL is unable to observe as many high clouds as CALIPSO due to being more frequently attenuated and a poorer sensitivity even in otherwise clear-sky conditions. After accounting for cloud fraction differences and instrument sampling differences due to viewing platform we determined that differences in cloud radiative forcing due to the retrieved ice cloud properties is relatively small. This study demonstrates that A-train observations are better suited for the calculation cloud radiative forcing profiles. In addition, we find that it is necessary to supplement CloudSat with CALIPSO observations to obtain accurate cloud radiative forcing profiles since a large portion of clouds at Darwin are detected by CALIPSO only.

Thorsen, Tyler J.; Fu, Qiang; Comstock, Jennifer M.

2013-06-11T23:59:59.000Z

199

Raman studies of corrosion layers formed on archaeological irons in various media  

E-Print Network [OSTI]

147 Raman studies of corrosion layers formed on archaeological irons in various media Ludovic mandana.saheb@cea.fr, f philippe.dillmann@cea.fr Keywords: Raman spectroscopy, iron corrosion, ancient artefact, imaging. Abstract. The description and identification of corrosion products formed

200

In situ Raman spectroscopy of lanthanum-strontium-cobaltite thin films  

E-Print Network [OSTI]

Raman spectroscopy is used to probe the structural change of Lanthanum Strontium Cobaltite (La1.xSrxCoO 3 -8) thin films across change in composition (0%-60% strontium) and temperature (30*C-520°C). Raman shift peaks were ...

Breucop, Justin Daniel

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Raman spectroscopy of carbon dust samples from NSTX Y. Raitses a,*, C.H. Skinner a  

E-Print Network [OSTI]

for the diagnosis of the microscopic structure of different forms of carbon. The intensity of D-mode at 1350 cmÃ?1Raman spectroscopy of carbon dust samples from NSTX Y. Raitses a,*, C.H. Skinner a , F. Jiang b , T. The Raman measurements indicate that the production of carbon dust particles in NSTX involves modifications

Duffy, Thomas S.

202

Raman intensity measurements of single-walled carbon nanotube suspensions as a quantitative technique  

E-Print Network [OSTI]

Raman intensity measurements of single-walled carbon nanotube suspensions as a quantitative, Biological and Materials Engineering, Carbon Nanotube Technology Center (CANTEC), University of Oklahoma, 100 the purity of single-walled carbon nanotube (SWCNT) bulk samples based on Raman spectroscopy is reported

Resasco, Daniel

203

RAMAN SPECTROSCOPY OF MACROSCALE FIBERS COMPRISED OF CARBON NANOTUBES OF DIFFERENT  

E-Print Network [OSTI]

RAMAN SPECTROSCOPY OF MACROSCALE FIBERS COMPRISED OF CARBON NANOTUBES OF DIFFERENT LENGTHS UNDER University Carbon nanotube (CNT) fibers are considered an excellent material for high performance engineering) Fibers Raman Spectroscopy of Macroscopic Fibers Spun from Carbon Nanotubes under Tensile Strain D

Mellor-Crummey, John

204

Indian Academy of Sciences C V Raman Avenue, Sadashivanagar, Bangalore 560 080  

E-Print Network [OSTI]

Indian Academy of Sciences C V Raman Avenue, Sadashivanagar, Bangalore 560 080 The Academy or email before 20 December 2013 to: The Executive Secretary Indian Academy of Sciences C V Raman Avenue: 1. The Academy reserves the right to restrict the number of candidates for interview to a reasonable

Joshi, Yogesh Moreshwar

205

THE JOURNAL OF CHEMICAL PHYSICS 134, 234310 (2011) False estimates of stimulated Raman pumping efficiency caused  

E-Print Network [OSTI]

THE JOURNAL OF CHEMICAL PHYSICS 134, 234310 (2011) False estimates of stimulated Raman pumping June 2011; published online 20 June 2011) One technique for measuring the fraction of molecules pumped to the excited state in stimulated Raman pumping (SRP) is to record the depletion of molecules in the lower state

Zare, Richard N.

206

Raman excitation profiles for the (n1, n2) assignment in carbon nanotubes  

E-Print Network [OSTI]

Raman excitation profiles for the (n1, n2) assignment in carbon nanotubes H. Telg , J. Maultzsch indices n1 and n2 in semiconducting and metallic nanotubes was performed comparing resonance Raman nanotube families. Ever since the discovery of how to keep isolated nanotubes from rebundeling in solu

Nabben, Reinhard

207

10.1098/rsta.2004.1444 Resonant Raman spectroscopy of nanotubes  

E-Print Network [OSTI]

10.1098/rsta.2004.1444 Resonant Raman spectroscopy of nanotubes By Christian Thomsen1 , Stephanie. The experimental situation in carbon nanotubes is reviewed in view of these criteria. The evidence for the D mode for the application of Raman scattering to the characterization of nanotubes are discussed. Keywords: carbon nanotubes

Nabben, Reinhard

208

POLARIZED RAMAN MEASUREMENTS IN ZEOLITE-GROWN SINGLE-WALL CARBON NANOTUBES  

E-Print Network [OSTI]

POLARIZED RAMAN MEASUREMENTS IN ZEOLITE-GROWN SINGLE-WALL CARBON NANOTUBES J. Maultzsch*, P. M, Hardenbergstr. 36, D-10623 Berlin, E-Mail: janina@physik.tu-berlin.de The Raman spectra of carbon nanotubes able to grow carbon nanotubes inside the channels of an AlPO4 zeolite crystal [1]. The directions

Nabben, Reinhard

209

Raman characterization of boron-doped multiwalled carbon nanotubes J. Maultzsch,a)  

E-Print Network [OSTI]

. We interpret this result as an indication that the high-energy mode in carbon nanotubes is defectRaman characterization of boron-doped multiwalled carbon nanotubes J. Maultzsch,a) S. Reich, and C of boron-doped multiwalled carbon nanotubes. The Raman intensities are analyzed as a function

Nabben, Reinhard

210

Raman scattering in carbon nanotubes Technische Universitat Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany  

E-Print Network [OSTI]

in carbon nanotubes is the strong excitation-energy dependent Raman shift of the socalled D-mode, which for instance for metallic nanotubes near the K-point. For a given incident photon energy, there is an incomingRaman scattering in carbon nanotubes C. Thomsen Technische Universit¨at Berlin, Hardenbergstrasse

Nabben, Reinhard

211

Origin of the high-energy Raman modes in single-wall carbon nanotubes  

E-Print Network [OSTI]

Origin of the high-energy Raman modes in single-wall carbon nanotubes J. Maultzsch, C. Thomsen, S nanotubes. Similar to the disorder-induced D mode, the high-energy modes are deter- mined by double of the first-order high-energy Raman modes in carbon nanotubes has been a puzzling question since the first

Nabben, Reinhard

212

Raman spectroscopy on single and multi-walled nanotubes under high pressure  

E-Print Network [OSTI]

dependence of the high-energy Raman modes in single and multi-walled carbon nanotubes was measuredRaman spectroscopy on single and multi-walled nanotubes under high pressure C. Thomsen, S. Reich, H properties of carbon nanotubes have become of scienti c interest since it was recognized that the low atomic

Nabben, Reinhard

213

Imaging Lignin-Downregulated Alfalfa Using Coherent Anti-Stokes Raman Scattering Microscopy  

E-Print Network [OSTI]

Imaging Lignin-Downregulated Alfalfa Using Coherent Anti-Stokes Raman Scattering Microscopy Yining-downregulated alfalfa lines were imaged using coherent anti-Stokes Raman scattering (CARS) microscopy. The 1,600-cm-1 (CARS) . Lignin-downregulated alfalfa Introduction Lignocellulosic biomass is under consideration

Xie, Xiaoliang Sunney

214

Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates  

E-Print Network [OSTI]

Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates of magnesium sulfates on the martian surface. In situ identification of the hydration states of magnesium of magnesium sulfate. Characteristic and distinct Raman spectral patterns were observed for each of the 11

215

Breaking the Stokesanti-Stokes symmetry in Raman heterodyne detection of magnetic-resonance transitions  

E-Print Network [OSTI]

is the source of the Raman field. The Raman wave is phase locked to the excit- ing laser field heterodyne detection, using the excitation laser as the local oscillator. In this case, the two sidebands that contains a coherent excitation. Figure 1 schematically shows the simplest quantum-mechanical system

Suter, Dieter

216

Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump  

E-Print Network [OSTI]

Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump A. Fisch Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 and Department of Astrophysical Laser pulse compression­amplification through Raman backscattering in plasmas can be facilitated

217

UV Resonance Raman Characterization of Polycyclic Aromatic Hydrocarbons in Coal Liquid Distillates*  

E-Print Network [OSTI]

UV Resonance Raman Characterization of Polycyclic Aromatic Hydrocarbons in Coal Liquid Distillates samples, such as petroleum and coal, or for man-made samples, such as coal liquids, a major desire- nique for studying coal-liquid samples. 1-4 We demon- strated that the Raman spectra of polycyclic

Asher, Sanford A.

218

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

SciTech Connect (OSTI)

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

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

2014-07-28T23:59:59.000Z

219

Molecular dynamics in liquid cyclopropane. Raman and magnetic nuclear resonance studies  

E-Print Network [OSTI]

723 Molecular dynamics in liquid cyclopropane. II. 2014 Raman and magnetic nuclear resonance as a function of temperature (155, 300 K) and pressure (up to 3 kilobars). 13C and 2H nuclear magnetic resonance experiments are performed in the same temperature range. The isotropic and anisotropic Raman profiles

Boyer, Edmond

220

Determination of substrate pinning in epitaxial and supported graphene layers via Raman scattering  

E-Print Network [OSTI]

The temperature-induced shift of the Raman G line in epitaxial graphene on SiC and Ni surfaces, as well as in graphene supported on SiO[subscript 2], is investigated with Raman spectroscopy. The thermal shift rate of ...

Ferralis, Nicola

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Laser-Scanning Coherent Anti-Stokes Raman Scattering Microscopy and Applications to Cell Biology  

E-Print Network [OSTI]

Laser-Scanning Coherent Anti-Stokes Raman Scattering Microscopy and Applications to Cell Biology Ji 11747-3157 USA ABSTRACT Laser-scanning coherent anti-Stokes Raman scattering (CARS) microscopy with fast., 1990). Duncan et al. constructed the first CARS microscope by use of two dye laser beams

Xie, Xiaoliang Sunney

222

Micro-Raman spectroscopy of refractive index microstructures in silicone-based hydrogel  

E-Print Network [OSTI]

Micro-Raman spectroscopy of refractive index microstructures in silicone-based hydrogel polymers 26, 2009 (Doc. ID 102944); published March 3, 2009 Micro-Raman spectroscopy was used to study transparent hydro- gel polymer materials through a high (or medium) nu- merical aperture (NA) objective

Novotny, Lukas

223

Realignment-enhanced coherent anti-Stokes Raman scattering (CARS) and three-dimensional imaging in anisotropic fluids  

E-Print Network [OSTI]

We apply coherent anti-Stokes Raman Scattering (CARS) microscopy to characterize director structures in liquid crystals.

A. V. Kachynski; A. N. Kuzmin; P. N. Prasad; I. I. Smalyukh

2008-07-04T23:59:59.000Z

224

Detection and quantitative analysis of ferrocyanide and ferricyanide: FY 93 Florida State University Raman spectroscopy report  

SciTech Connect (OSTI)

This report provides a summary of work to develop and investigate the feasibility of using Raman spectroscopy with tank waste materials. It contains Raman spectra from organics, such as ethylenediaminetetraacetic acid (EDTA), hydroxyethylenediaminetetraacteic acid (HEDTA), imino diacetic acid (IDA), kerosene, tributyl phosphate (TBP), acetone and butanol, anticipated to be present in tank wastes and spectra from T-107 real and BY-104 simulant materials. The results of investigating Raman for determining moisture content in tank materials are also presented. A description of software algorithms developed to process Raman spectra from a dispersive grating spectrometer system and an in initial design for a data base to support qualitative and quantitative application of remote Raman sensing with tank wastes.

Mann, C.K.; Vickers, T.J. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry

1994-10-11T23:59:59.000Z

225

The effect of substrates on the Raman spectrum of graphene: Graphene-on-sapphire and graphene-on-glass  

E-Print Network [OSTI]

The effect of substrates on the Raman spectrum of graphene: Graphene- on-sapphire and graphene The authors investigated the influence of substrates on Raman scattering spectrum from graphene. The room-temperature Raman signatures from graphene layers on GaAs, sapphire, and glass substrates were compared with those

226

785 nm Raman Spectroscopy of CVD Diamond Films Paul William May, James A Smith, and Keith N Rosser  

E-Print Network [OSTI]

. Here, we report that when using 785 nm excitation, the Raman spectra from thin polycrystalline diamond785 nm Raman Spectroscopy of CVD Diamond Films Paul William May, James A Smith, and Keith N Rosser Raman spectroscopy is a powerful technique often used to study CVD diamond films, however, very little

Bristol, University of

227

Pump side scattering in ultrapowerful backward Raman amplifiers A. A. Solodov, V. M. Malkin, and N. J. Fisch  

E-Print Network [OSTI]

Pump side scattering in ultrapowerful backward Raman amplifiers A. A. Solodov, V. M. Malkin, and N of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even scattering of laser pumps by plasma noise in backward Raman amplifiers. Though its growth rate is smaller

228

New C-H Stretching Vibrational Spectral Features in the Raman Spectra of Gaseous and Liquid Ethanol  

E-Print Network [OSTI]

New C-H Stretching Vibrational Spectral Features in the Raman Spectra of Gaseous and Liquid Ethanol Traditionally, the Raman spectrum of ethanol in the C-H vibrational stretching region between 2800 cm-1 and 3100, and the -CH3 antisymmetric stretching. In this report, new Raman spectral features were observed for ethanol

Liu, Shilin

229

Sedimentological Reinterpretation of Surficial Unconsolidated Debris Flows and Stream Deposits of the Southern Flanks of Grand Mesa, CO: An Integrated LiDAR Approach  

E-Print Network [OSTI]

. This study developed a sedimentological description and interpretation of these deposits and tested the capabilities of terrestrial LiDAR (Light Detection and Ranging) for use in sedimentological studies. This research addressed the origin of the deposits...

Blakeley, Mitchell W.

2014-08-08T23:59:59.000Z

230

Surface-enhanced raman optical data storage system  

DOE Patents [OSTI]

An improved Surface-Enhanced Raman Optical Data Storage System (SERODS) is disclosed. In the improved system, entities capable of existing in multiple reversible states are present on the storage device. Such entities result in changed Surface-Enhanced Raman Scattering (SERS) when localized state changes are effected in less than all of the entities. Therefore, by changing the state of entities in localized regions of a storage device, the SERS emissions in such regions will be changed. When a write-on device is controlled by a data signal, such a localized regions of changed SERS emissions will correspond to the data written on the device. The data may be read by illuminating the surface of the storage device with electromagnetic radiation of an appropriate frequency and detecting the corresponding SERS emissions. Data may be deleted by reversing the state changes of entities in regions where the data was initially written. In application, entities may be individual molecules which allows for the writing of data at the molecular level. A read/write/delete head utilizing near-field quantum techniques can provide for a write/read/delete device capable of effecting state changes in individual molecules, thus providing for the effective storage of data at the molecular level.

Vo-Dinh, Tuan (Knoxville, TN)

1994-01-01T23:59:59.000Z

231

Surface-Enhanced Raman Optical Data Storage system  

DOE Patents [OSTI]

An improved Surface-Enhanced Raman Optical Data Storage System (SERODS) is disclosed. In the improved system, entities capable of existing in multiple reversible states are present on the storage device. Such entities result in changed Surface-Enhanced Raman Scattering (SERS) when localized state changes are effected in less than all of the entities. Therefore, by changing the state of entities in localized regions of a storage device, the SERS emissions in such regions will be changed. When a write-on device is controlled by a data signal, such a localized regions of changed SERS emissions will correspond to the data written on the device. The data may be read by illuminating the surface of the storage device with electromagnetic radiation of an appropriate frequency and detecting the corresponding SERS emissions. Data may be deleted by reversing the state changes of entities in regions where the data was initially written. In application, entities may be individual molecules which allows for the writing of data at the molecular level. A read/write/delete head utilizing near-field quantum techniques can provide for a write/read/delete device capable of effecting state changes in individual molecules, thus providing for the effective storage of data at the molecular level. 18 figures.

Vo-Dinh, T.

1994-06-28T23:59:59.000Z

232

Comparing Pulsed Doppler LIDAR with SODAR and Direct Measurements for Wind Assessment  

SciTech Connect (OSTI)

There is a pressing need for good wind-speed measurements at greater and greater heights to assess the availability of the resource in terms of power production and to identify any frequently occurring atmospheric structural characteristics that may create turbulence that impacts the operational reliability and lifetime of wind turbines and their components. In this paper, we summarize the results of a short study that compares the relative accuracies of wind speeds derived from a high-resolution pulsed Doppler LIDAR operated by the National Oceanic and Atmospheric Administration (NOAA) and a midrange Doppler SODAR with wind speeds measured by four levels of tower-based sonic anemometry up to a height of 116 m.

Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Pichugina, Y. L.

2007-07-01T23:59:59.000Z

233

Synthesis and characterization of mixed monolayer protected gold nanorods and their Raman activities  

SciTech Connect (OSTI)

Graphical abstract: Gold nanorods surface functionalization. - Highlights: • Mixed monolayer protected gold nanorods. • Surface enhanced Raman spectroscopy. • HS-(CH{sub 2}){sub 11}-NHCO-coumarin as a Raman active compound. - Abstract: The cetyltrimethylammonium bromide (CTAB) gold nanorods (AuNRs) were prepared by seed-mediated route followed by the addition of a Raman active compound (HS-(CH{sub 2}){sub 11}-NHCO-coumarin) on the gold nanorods surfaces. Different stoichiometric mixtures of HS-(CH{sub 2}){sub 11}-NHCO-coumarin and HS-PEG-(CH{sub 2}){sub 11}COOH were evaluated for their Raman activities. The lowest stoichiometric ratio HS-(CH{sub 2}){sub 11}-NHCO-coumarin adsorbed on gold nanorods surface was detected and enhanced by Raman spectroscopy. The produced mixed monolayer protected gold nanorods were characterized by UV-vis spectrometer for optical properties, transmission electron microscope (TEM) for structural properties (shape and aspect ratio) and their zeta potentials (charges) were obtained from ZetaSizer to determine the stability of the produced mixed monolayer protected gold nanorods. The Raman results showed a surface enhanced Raman scattering (SERS) enhancement at the lowest stoichiometric ratio of 1% HS-(CH{sub 2}){sub 11}-NHCO-coumarin compared to high ratio of 50% HS-(CH{sub 2}){sub 11}-NHCO-coumarin on the surface of gold nanorods.

Mlambo, Mbuso [Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Wits 2050 (South Africa); Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125 (South Africa); Mdluli, Phumlani S.; Shumbula, Poslet; Mpelane, Siyasanga [Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125 (South Africa); Moloto, Nosipho, E-mail: Nosipho.Moloto@wits.ac.za [Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Wits 2050 (South Africa); Skepu, Amanda; Tshikhudo, Robert [Nanotechnology Innovation Centre, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125 (South Africa)

2013-10-15T23:59:59.000Z

234

Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.  

DOE Patents [OSTI]

A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. A low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic transaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively.

Alfano, Robert R. (Bronx, NY); Wang, Wubao (Flushing, NY)

2003-05-06T23:59:59.000Z

235

Rayleigh LIDAR and satellite (HALOE, SABER, CHAMP and COSMIC) measurements of stratosphere-mesosphere temperature over a southern sub-tropical site, Reunion (20.8° S; 55.5° E): climatology and comparison study  

E-Print Network [OSTI]

climatology of the mid- dle atmosphere from long-termLIDAR measurements at mid- dle and low latitudes, J.Over the southern tropics, mid- dle atmosphere temperature

Sivakumar, V.; Vishnu Prasanth, P.; Kishore, P.; Bencherif, H.; Keckhut, P.

2011-01-01T23:59:59.000Z

236

Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.  

DOE Patents [OSTI]

A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. In accordance with the teachings of the invention, a low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic tansaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively. For example, it may also be used to diagnose diseases associated with the concentration of Raman-active constituents in urine, lymph and saliva It may be used to identify cancer in the breast, cervix, uterus, ovaries and the like by measuring the fingerprint excitation Raman spectra of these tissues. It may also be used to reveal the growing of tumors or cancers by measuring the levels of nitric oxide in tissue.

Alfano, Robert R. (Bronx, NY); Wang, Wubao (Flushing, NY)

2000-11-21T23:59:59.000Z

237

Q-branch Raman scattering and modern kinetic thoery  

SciTech Connect (OSTI)

The program is an extension of previous APL work whose general aim was to calculate line shapes of nearly resonant isolated line transitions with solutions of a popular quantum kinetic equation-the Waldmann-Snider equation-using well known advanced solution techniques developed for the classical Boltzmann equation. The advanced techniques explored have been a BGK type approximation, which is termed the Generalized Hess Method (GHM), and conversion of the collision operator to a block diagonal matrix of symmetric collision kernels which then can be approximated by discrete ordinate methods. The latter method, which is termed the Collision Kernel method (CC), is capable of the highest accuracy and has been used quite successfully for Q-branch Raman scattering. The GHM method, not quite as accurate, is applicable over a wider range of pressures and has proven quite useful.

Monchick, L. [The Johns Hopkins Univ., Laurel, MD (United States)

1993-12-01T23:59:59.000Z

238

Detection of volatile organic compounds using surface enhanced Raman scattering  

SciTech Connect (OSTI)

The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.

Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C

2012-03-22T23:59:59.000Z

239

Surface enhanced Raman gene probe and methods thereof  

DOE Patents [OSTI]

The subject invention disclosed herein is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

Vo-Dinh, T.

1998-09-29T23:59:59.000Z

240

Surface enhanced Raman gene probe and methods thereof  

DOE Patents [OSTI]

The subject invention disclosed is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

Vo-Dinh, T.

1998-07-21T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Nanosensors based on functionalized nanoparticles and surface enhanced raman scattering  

DOE Patents [OSTI]

Surface-Enhanced Raman Spectroscopy (SERS) is a vibrational spectroscopic technique that utilizes metal surfaces to provide enhanced signals of several orders of magnitude. When molecules of interest are attached to designed metal nanoparticles, a SERS signal is attainable with single molecule detection limits. This provides an ultrasensitive means of detecting the presence of molecules. By using selective chemistries, metal nanoparticles can be functionalized to provide a unique signal upon analyte binding. Moreover, by using measurement techniques, such as, ratiometric received SERS spectra, such metal nanoparticles can be used to monitor dynamic processes in addition to static binding events. Accordingly, such nanoparticles can be used as nanosensors for a wide range of chemicals in fluid, gaseous and solid form, environmental sensors for pH, ion concentration, temperature, etc., and biological sensors for proteins, DNA, RNA, etc.

Talley, Chad E. (Brentwood, CA); Huser, Thomas R. (Livermore, CA); Hollars, Christopher W. (Brentwood, CA); Lane, Stephen M. (Oakland, CA); Satcher, Jr., Joe H. (Patterson, CA); Hart, Bradley R. (Brentwood, CA); Laurence, Ted A. (Livermore, CA)

2007-11-27T23:59:59.000Z

242

Surface enhanced Raman gene probe and methods thereof  

DOE Patents [OSTI]

The subject invention disclosed is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

Vo-Dinh, T.

1998-02-24T23:59:59.000Z

243

Multiphonon resonant Raman scattering in MoS{sub 2}  

SciTech Connect (OSTI)

Optical emission spectrum of a resonantly (??=?632.8?nm) excited molybdenum disulfide (MoS{sub 2}) is studied at liquid helium temperature. More than 20 peaks in the energy range spanning up to 1400?cm{sup ?1} from the laser line, which are related to multiphonon resonant Raman scattering processes, are observed. The attribution of the observed lines involving basic lattice vibrational modes of MoS{sub 2} and both the longitudinal (LA(M)) and the transverse (TA(M) and/or ZA(M)) acoustic phonons from the vicinity of the high-symmetry M point of the MoS{sub 2} Brillouin zone is proposed.

Go?asa, K., E-mail: Katarzyna.Golasa@fuw.edu.pl; Grzeszczyk, M.; Wysmo?ek, A.; Babi?ski, A. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warszawa (Poland); Leszczy?ski, P.; Faugeras, C.; Nicolet, A. A. L.; Potemski, M. [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble (France)

2014-03-03T23:59:59.000Z

244

Third harmonic stimulated Raman backscattering of laser in a magnetized plasma  

SciTech Connect (OSTI)

This article studies the nonlinear Raman shifted third harmonic backscattering of an intense extraordinary laser wave through a homogenous transversely magnetized cold plasma. Due to the relativistic nonlinearity, the plasma dynamic is modified in the presence of transversely magnetic field, and this can generate the third harmonic scattered wave and an electrostatic upper hybrid wave via the Raman scattering process. Using the nonlinear wave equation, the mechanism of nonlinear third harmonic Raman scattering is discussed in detail to obtain the maximum growth rate of instability in the mildly relativistic regime. The growth rate decreases as the static magnetic field increases. It also increases with the pump wave amplitude.

Paknezhad, Alireza [Physics Department, Shabestar Branch, Islamic Azad University, Shabestar (Iran, Islamic Republic of)] [Physics Department, Shabestar Branch, Islamic Azad University, Shabestar (Iran, Islamic Republic of); Dorranian, Davoud [Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)] [Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

2013-09-15T23:59:59.000Z

245

Raman shifted third harmonic generation of upper hybrid radiation in a plasma  

SciTech Connect (OSTI)

Raman shifted third harmonic generation of upper hybrid radiation is proposed and studied. In the presence of ambient magnetic field, the plasma wave present in the system produces electron density ripple (perturbation) which couples with the velocity imparted by the nonlinear ponderomotive force at twice the laser frequency producing the Raman shifted third harmonic field. The wave vector of the plasma wave provides the uncompensated momentum necessary for phase matching condition. The applied magnetic field can be adjusted to have the phase matching for the given plasma frequency. The energy conversion ratio from pump to the Raman shifted third harmonic generation of upper hybrid radiation is analyzed.

Magesh Kumar, K.K.; Singh, Ranjeet; Tripathi, V. K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016 (India)

2012-11-15T23:59:59.000Z

246

Time?resolved anisotropic coherent anti?Stokes Raman scattering: A new probe of reorientational dynamics  

E-Print Network [OSTI]

anti-Stokes Raman scattering (TRA CARS) and spontaneous Raman (TRA Raman) as probes of rota­ tional motion. II. THEORY When a sample system is illuminated by three laser beams at frequencies (Uo, (UI, and (U2, the incident fields induce a third... is described by a nonlinear sus­ ceptibility tensor containing three independent compo­ nents in the L=O subspace and six independent compo­ nents in the L = 2 subspace. First we write the molecular susceptibility MU11(0) iIi terms of the direct product...

Wan, Chaozhi; Johnson, Carey K.

1993-09-01T23:59:59.000Z

247

Solar Energy Materials & Solar Cells 71 (2002) 511522 In situ Raman spectroscopy of the  

E-Print Network [OSTI]

Solar Energy Materials & Solar Cells 71 (2002) 511­522 In situ Raman spectroscopy. In this situation, a low energy excitation (e.g. visible light) is needed to excite an electron to a neighboring

Nabben, Reinhard

248

Diradicals acting through diamagnetic phenylene vinylene bridges: Raman spectroscopy as a probe to characterize spin delocalization  

SciTech Connect (OSTI)

We present a complete Raman spectroscopic study in two structurally well-defined diradical species of different lengths incorporating oligo p-phenylene vinylene bridges between two polychlorinated triphenylmethyl radical units, a disposition that allows sizeable conjugation between the two radicals through and with the bridge. The spectroscopic data are interpreted and supported by quantum chemical calculations. We focus the attention on the Raman frequency changes, interpretable in terms of: (i) bridge length (conjugation length); (ii) bridge conformational structure; and (iii) electronic coupling between the terminal radical units with the bridge and through the bridge, which could delineate through-bond spin polarization, or spin delocalization. These items are addressed by using the “oligomer approach” in conjunction with pressure and temperature dependent Raman spectroscopic data. In summary, we have attempted to translate the well-known strategy to study the electron (charge) structure of ??conjugated molecules by Raman spectroscopy to the case of electron (spin) interactions via the spin delocalization mechanism.

González, Sandra Rodríguez; Nieto-Ortega, Belén; González Cano, Rafael C.; López Navarrete, Juan T., E-mail: vecianaj@icmab.es, E-mail: teodomiro@uma.es, E-mail: casado@uma.es; Casado, Juan, E-mail: vecianaj@icmab.es, E-mail: teodomiro@uma.es, E-mail: casado@uma.es [Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, Málaga 29071 (Spain)] [Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n, Málaga 29071 (Spain); Lloveras, Vega; Vidal-Gancedo, José; Rovira, Concepció; Veciana, Jaume, E-mail: vecianaj@icmab.es, E-mail: teodomiro@uma.es, E-mail: casado@uma.es [Department of Molecular Nanoscience and Organic Materials, Institut de Ciència de Materials de Barcelona (CSIC), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Barcelona (Spain) [Department of Molecular Nanoscience and Organic Materials, Institut de Ciència de Materials de Barcelona (CSIC), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Barcelona (Spain); NANOMOL group, Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Campus Universitari de Bellaterra, E-08193 Cerdanyola, Barcelona (Spain); Novoa, Juan J.; Mota, Fernando [Dpt. de Química Física and IQTCUB, Fac. Química, Univ. de Barcelona, Av. Diagonal, 647, 08028-Barcelona (Spain)] [Dpt. de Química Física and IQTCUB, Fac. Química, Univ. de Barcelona, Av. Diagonal, 647, 08028-Barcelona (Spain); Corro, Elena del; Taravillo, Mercedes; Baonza, Valentín G. [MALTA-Consolider Team, Department of Physical Chemistry, University Complutense of Madrid, Madrid 28040 (Spain)] [MALTA-Consolider Team, Department of Physical Chemistry, University Complutense of Madrid, Madrid 28040 (Spain)

2014-04-28T23:59:59.000Z

249

Beyond Myopic Inference in Big Data Pipelines Karthik Raman, Adith Swaminathan, Johannes Gehrke, Thorsten Joachims  

E-Print Network [OSTI]

]: Learning General Terms Algorithms, Experimentation, Theory Keywords Big Data Pipelines, Modular Design Detection & Recognition pipeline. creation, model construction, testing, and visualization. In orderBeyond Myopic Inference in Big Data Pipelines Karthik Raman, Adith Swaminathan, Johannes Gehrke

Joachims, Thorsten

250

Detection of bacterial endospores by means of ultrafast coherent raman spectroscopy  

E-Print Network [OSTI]

This work is devoted to formulation and development of a laser spectroscopic technique for rapid detection of biohazards, such as Bacillus anthracis spores. Coherent anti-Stokes Raman scattering (CARS) is used as an underlying process for active...

Pestov, Dmitry Sergeyevich

2008-10-10T23:59:59.000Z

251

Raman excitation profile of the G band in single-chirality carbon nanotubes  

E-Print Network [OSTI]

We present in this work measurements of the Raman excitation profile of the high-energy phonons (G band) in single-chirality (n,m) semiconducting single-wall carbon nanotubes using more than 70 laser excitation energies, ...

Moura, L. G.

252

Resonance Raman spectroscopy in Si and C ion-implanted double-wall carbon nanotubes  

E-Print Network [OSTI]

The effect of 170 keV Si and 100 keV C ion bombardment on the structure and properties of highly pure, double-wall carbon nanotubes has been investigated using resonance Raman spectroscopy. The implantations were performed ...

Dresselhaus, Mildred

253

Mapping residual stress fields from Vickers hardness indents using Raman microprobe spectroscopy  

SciTech Connect (OSTI)

Micro-Raman spectroscopy is used to map the residual stress fields in the vicinity of Vickers hardness indents. Both 514.5 and 488.0 nm, light is used to excite the effect and the resulting shifted and broadened Raman peaks are analyzed using computer deconvolution. Half-wave plates are used to vary the orientation of the incident later light`s polarization state with respect to crystal orientation. The Raman scattered light is then analyzed for polarization dependences which are indicative of the various components of the Raman scattering tensor. Such studies can yield valuable information about the orientation of stress components in a well known stress field. The results can then be applied to the determination of stress components in machined semiconductor materials.

Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

1988-12-01T23:59:59.000Z

254

Fingerprint and high-wavenumber Raman spectroscopy in a human-swine coronary xenograft in vivo  

E-Print Network [OSTI]

Intracoronary Raman spectroscopy could open new avenues for the study and management of coronary artery disease due to its potential to measure the chemical and molecular composition of coronary atherosclerotic lesions. ...

Motz, Jason T.

255

Zone folding effect in Raman G-band intensity of twisted bilayer graphene  

E-Print Network [OSTI]

The G-band Raman intensity is calculated for twisted bilayer graphene as a function of laser excitation energy based on the extended tight binding method. Here we explicitly consider the electron-photon and electron-phonon ...

Dresselhaus, Mildred

256

UV Resonance Raman Spectroscopy Using a New cw Laser Source: Convenience and Experimental Simplicity  

E-Print Network [OSTI]

into the spectrometer. We dem- onstrate the ability of this laser to excite Raman spectra of solid samples such as coal-liquid- alytical applications. Examples include studies of PAHs in coal-derived liquids4-~and in petroleum

Asher, Sanford A.

257

Double resonance Raman spectra of graphene : a full 2D calculation  

E-Print Network [OSTI]

Visible range Raman spectra of graphene are generated based on the double resonant process employing a full two-dimensional numerical calculation applying second-order perturbation theory. Tight binding expressions for ...

Narula, Rohit

2007-01-01T23:59:59.000Z

258

Uniaxial strain in graphene by Raman spectroscopy: G peak splitting, Grüneisen parameters, and sample orientation  

E-Print Network [OSTI]

We uncover the constitutive relation of graphene and probe the physics of its optical phonons by studying its Raman spectrum as a function of uniaxial strain. We find that the doubly degenerate E[subscript 2g] optical mode ...

Mohiuddin, T. M. G.

259

Rotational-Vibrational Raman Spectroscopy for Measurements of Thermochemistry in Non-isobaric Environments  

E-Print Network [OSTI]

The present work examines line measurements of pressure, temperature, and density in high speed, non-isobaric flows emanating from an underexpanded jet nozzle. Line images of rotational and vibrational Raman spectra are collected for a 8-mm linear...

Bayeh, Alexander C.

2010-01-14T23:59:59.000Z

260

Raman spectroscopy for characterization of annealing of ion-implanted InP  

SciTech Connect (OSTI)

Raman spectroscopy has been used as a noncontacting, nondestructive tool to evaluate the properties of Si/sup +/- and Be/sup +/- implanted InP samples annealed at temperatures ranging from 600 to 750C using phosphosilicate glass (PSG) as the encapsulant. Carrier activation, carrier mobility and recovery of damage as a function of anneal temperature obtained from analysis of Raman data agree very well with independent electrical measurements.

Myers, D.R.; Gourley, P.L.; Vaidyanathan, K.V.; Dunlap, H.L.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

X-ray Raman compression via two-stream instability in dense plasmas  

E-Print Network [OSTI]

A Raman compression scheme suitable for x-rays, where the Langmuir wave is created by an intense beam rather than the pondermotive potential between the seed and pump pulses, is proposed. The required intensity of the seed and pump pulses enabling the compression could be mitigated by more than a factor of 100, compared to conventionally available other Raman compression schemes. The relevant wavelength of x-rays ranges from 1 to 10 nm.

S. Son; Sung Joon Moon

2011-03-27T23:59:59.000Z

262

Summary of raman cone penetrometer probe waste tank radiation and chemical environment test  

SciTech Connect (OSTI)

This report summarizes the results of testing Raman sapphire windows that were braze mounted into a mockup Raman probe head and stainless steel coupons in a simulated tank waste environment. The simulated environment was created by exposing sapphire window components, immersed in a tank simulant, in a gamma pit. This work was completed for the U.S. Department of Energy (DOE) Office of Environmental Management (EM-50) for Technical Task Proposal RL4-6-WT-21.

Reich, F.R.

1996-09-27T23:59:59.000Z

263

University of Wisconsin High Spectral Lidar operations during MPACE: Examples of AHSRL-MMCR particle size retrievals E.W.Eloranta, I.A.Razenkov, J.P.Garcia, and J.P.Hedrick  

E-Print Network [OSTI]

where valid lidar and radar measurements were obtained. 6) Lidar and radar data were averaged and altitude bins.Measurements within 6 dBZ of the radar's minimum detectable reflectivity are removed along signal-to-noise level can also be specified to exclude noisy data points AHSRL data was used extensively

Eloranta, Edwin W.

264

Measuring depth profiles of residual stress with Raman spectroscopy  

SciTech Connect (OSTI)

Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

Enloe, W.S.; Sparks, R.G.; Paesler, M.A.

1988-12-01T23:59:59.000Z

265

Micro-Raman spectroscopic study of nanolaminated Ti{sub 5}Al{sub 2}C{sub 3}  

SciTech Connect (OSTI)

Micro-Raman spectroscopic study and lattice dynamics calculations were conducted to study a recently identified layered ternary carbide, Ti{sub 5}Al{sub 2}C{sub 3}. The experimental Raman shifts were remarkably consistent with the calculated values. Polarized Raman spectrum was collected in the polycrystalline sample, which confirmed the theoretical symmetry assignment of the Raman modes. In addition, the atomic vibrations of the peaks at 192?cm{sup ?1}, 311?cm{sup ?1}, and 660?cm{sup ?1} were identified to be the combination of the counterparts in Ti{sub 2}AlC and Ti{sub 3}AlC{sub 2}.

Zhang, H.; Li, Z. J. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, X. H. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Xiang, H. M.; Zhou, Y. C, E-mail: yczhou714@gmail.com [Science and Technology of Advanced Functional Composite Laboratory, ARIMPT, No.1 South Dahongmen Road, Beijing 100076 (China)

2014-03-31T23:59:59.000Z

266

A digital map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for Barrow, Alaska  

SciTech Connect (OSTI)

This dataset represent a map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for the arctic coastal plain at Barrow, Alaska. The polygon troughs are considered as the surface expression of the ice-wedges. The troughs are in lower elevations than the interior polygon. The trough widths were initially identified from LiDAR data, and the boundary between two polygons assumed to be located along the lowest elevations on trough widths between them.

Gangodagamage, Chandana; Wullschleger, Stan

2014-07-03T23:59:59.000Z

267

A digital map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for Barrow, Alaska  

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

This dataset represent a map of the high center (HC) and low center (LC) polygon boundaries delineated from high resolution LiDAR data for the arctic coastal plain at Barrow, Alaska. The polygon troughs are considered as the surface expression of the ice-wedges. The troughs are in lower elevations than the interior polygon. The trough widths were initially identified from LiDAR data, and the boundary between two polygons assumed to be located along the lowest elevations on trough widths between them.

Gangodagamage, Chandana; Wullschleger, Stan

268

Identification of minerals and meteoritic materials via Raman techniques after capture in hypervelocity impacts on aerogel  

SciTech Connect (OSTI)

For this study, an extensive suite of mineral particles analogous to components of cosmic dust were tested to determine if their Raman signatures can be recognized after hypervelocity capture in aerogel. The mineral particles were mainly of greater than 20 micrometers in size and were accelerated onto the silica aerogel by light gas gun shots. It was found that all the individual minerals captured in aerogel could be subsequently identified using Raman (or fluorescent) spectra. The beam spot size used for the laser illumination was of the order of 5 micrometers, and in some cases the captured particles were of a similar small size. In some samples fired into aerogel there was observed a shift in the wavenumbers of some of the Raman bands, a result of the trapped particles being at quite high temperatures due to heating by the laser. Temperatures of samples under laser illumination were estimated from the relative intensities of Stokes and anti-Stokes Raman bands, or, in the case of ruby particles, from the wavenumber of fluorescence bands excited by the laser. It was found that the temperature of particles in aerogel varied greatly, dependent upon laser power and the nature of the particle. In the worst case, some particles were shown to have temperatures in the 500-700 C range at a laser power of about 3 mW at the sample. However most of the mineral particles examined at this laser power had temperatures below 200 C. This is sufficiently low a temperature not to damage most materials expected to be found captured in aerogel in space. In addition, selected meteorite samples were examined to obtain Raman signatures of their constituent minerals and were then shot into aerogel. It was possible to find several Raman signatures after capture in aerogel and obtain a Raman map of a whole grain in situ in the aerogel. Finally, a Raman analysis was carried out of a particle captured in aerogel in space and carbonaceous material identified. In general therefore it is concluded that Raman analysis is indeed well suited for an in-situ analysis of micrometer sized non-terrestrial materials captured in aerogel.

Burchell, M J; Mann, J; Creighton, J A; Kearsley, A; Graham, G A; Esposito, A P; Franchi, I A; Westphal, A J; Snead, C

2004-10-04T23:59:59.000Z

269

Light trapping in thin-film solar cells measured by Raman spectroscopy  

SciTech Connect (OSTI)

In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (?c-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442?nm, 514?nm, 633?nm, and 785?nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the ?c-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infrared wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the ?c-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.

Ledinský, M., E-mail: ledinsky@fzu.cz [Laboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague (Czech Republic); Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Moulin, E.; Bugnon, G.; Meillaud, F.; Ballif, C. [Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Ganzerová, K.; Vetushka, A.; Fejfar, A. [Laboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague (Czech Republic)

2014-09-15T23:59:59.000Z

270

The effects of machine parameters on residual stress determined using micro-Raman spectroscopy  

SciTech Connect (OSTI)

The effects of machine parameters on residual stresses in single point diamond turned silicon and germanium have been investigated using micro-Raman spectroscopy. Residual stresses were sampled across ductile feed cuts in < 100 > silicon and germanium which were single point diamond turned using a variety of feed rates, rake angles and clearance angles. High spatial resolution micro-Raman spectra (1{mu}m spot) were obtained in regions of ductile cutting where no visible surface damage was present. The use of both 514-5nm and 488.0nm excitation wavelengths, by virtue of their differing characteristic penetration depths in the materials, allowed determinations of stress profiles as a function of depth into the sample. Previous discussions have demonstrated that such Raman spectra will exhibit asymmetrically broadened peaks which are characteristic of the superposition of a continuum of Raman scatterers from the various depths probed. Depth profiles of residual stress were obtained using computer deconvolution of the resulting asymmetrically broadened raman spectra.

Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

1988-12-01T23:59:59.000Z

271

Raman Database Considerations for Near-Infrared Systems  

SciTech Connect (OSTI)

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

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

2011-12-21T23:59:59.000Z

272

A joint study of the lower ionosphere by radar, lidar, and spectrometer  

SciTech Connect (OSTI)

The dynamics and associated phenomena occurring in the lower ionospheric-E region, especially the mesopause region between 80 km to 110 km at low latitude, are studied. In particular, incoherent scatter radar (ISR), sodium lidar and airglow spectrometry are used to study the ionospheric structure and neutral sodium structure. The simultaneous study of the ionospheric plasma and neutral atomic sodium is unprecedented in scope and detail. The joint study of the mesopause region reveals that plasma, neutral densities and temperature are interconnected through the same atmospheric dynamics. The theme of the thesis is to explain the formation of the controversial sporadic sodium layer (SSL) events. Strong correlation is established between the average total ion and sodium concentrations, and between sporadic-E and SSL events. The mechanism proposed in the thesis, which invokes temperature fluctuations induced by tides and gravity waves, finds good agreement with observations. Tides and gravity waves can converge ions into thin layers through the windshear mechanisms and can influence the concentration of atomic sodium through temperature fluctuations. Sodium abundance is shown to augment rapidly when the temperature is increased. Gravity wave theory states that the ion convergence node coincides with a temperature maximum for a westward propagating gravity wave, and coincides with a temperature minimum for an eastward propagating wave. Because tidal winds propagate westward, the ion layer coincides with the temperature maximum which consequently induces higher sodium concentration. This can account for the general correlation between sodium and total ion concentration and is supported by the O2(0-1) rotational temperature. Gravity waves and their interaction with tidal winds are believed to be responsible for the close association between sudden sodium layers and sporadic-E layers.

Zhou, Qihou.

1991-01-01T23:59:59.000Z

273

Fiber-optic apparatus and method for measurement of luminescence and raman scattering  

DOE Patents [OSTI]

A dual fiber forward scattering optrode for Raman spectroscopy with the remote ends of the fibers in opposed, spaced relationship to each other to form a analyte sampling space therebetween and the method of measuring Raman spectra utilizing same. One optical fiber is for sending an exciting signal to the remote sampling space and, at its remote end, has a collimating microlens and an optical filter for filtering out background emissions generated in the fiber. The other optical fiber is for collecting the Raman scattering signal at the remote sampling space and, at its remote end, has a collimating microlens and an optical filter to prevent the exciting signal from the exciting fiber from entering the collection fiber and to thereby prevent the generation of background emissions in the collecting fiber.

Myrick, Michael L. (Livermore, CA); Angel, Stanley M. (Livermore, CA)

1993-01-01T23:59:59.000Z

274

Raman Spectroscopy of Lithium Hydride Corrosion: Selection of an Appropriate Excitation Wavelength to Minimize Fluorescence  

SciTech Connect (OSTI)

The recent interest in a hydrogen-based fuel economy has renewed research into metal hydride chemistry. Many of these compounds react readily with water to release hydrogen gas and form a caustic. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT) has been used to study the hydrolysis reaction. The LiOH stretch appears at 3670 cm{sup -1}. Raman spectroscopy is a complementary technique that employs monochromatic excitation (laser) allowing access to the low energy region of the vibrational spectrum (<600 cm{sup -1}). Weak scattering and fluorescence typically prevent Raman from being used for many compounds. The role of Li{sub 2}O in the moisture reaction has not been fully studied for LiH. Li{sub 2}O can be observed by Raman while being hidden in the Infrared spectrum.

Stowe, A. C.; Smyrl, N. R.

2011-05-26T23:59:59.000Z

275

Relation between squeezing of vacuum fluctuations, quantum entanglement and sub-shot noise in Raman scattering  

E-Print Network [OSTI]

A completely quantum description of Raman process is used to investigate the nonclassical properties of the modes in the stimulated, spontaneous and partially spontaneous Raman process. Both coherent scattering (where all the initial modes are coherent) and chaotic scattering (where initial phonon mode is chaotic and all the other modes are coherent) are studied. Nonclassical character of Raman process is observed by means of intermodal entanglement, single mode and intermodal squeezing of vacuum fluctuations, sub-shot noise and wave variances. Joint photon-phonon number and integrated-intensity distributions are then used to illustrate the observed nonclassicalities. Conditional and difference number distributions are also provided to illustrate the nonclassical character. The mutual relation between the obtained nonclassicalities and their variations dependent on phases, rescalled time and ratio of coupling constants are also reported.

Anirban Pathak; Jaromir Krepelka; Jan Perina

2012-10-14T23:59:59.000Z

276

Synthesis of few layer graphene by direct exfoliation of graphite and a Raman spectroscopic study  

SciTech Connect (OSTI)

The exfoliation of graphene from pristine graphite in a liquid phase was achieved successfully via sonication followed by centrifugation method. Ultraviolet–visible (UV–vis) spectra of the obtained graphene dispersions at different exfoliation time indicated that the concentration of graphene dispersion increased markedly with increasing exfoliation time. The sheet-like morphology of the exfoliated graphene was revealed by Scanning Electron Microscopy (SEM) image. Further, the morphological change in different exfoliation time was investigated by Atomic Force Microscopy (AFM). A complete structural and defect characterization was probed using micro-Raman spectroscopic technique. The shape and position of the 2D band of Raman spectra revealed the formation of bilayer to few layer graphene. Also, Raman mapping confirmed the presence of uniformly distributed bilayer graphene sheets on the substrate.

Gayathri, S.; Jayabal, P.; Ramakrishnan, V., E-mail: vr.optics1@gmail.com [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625021, India. (India); Kottaisamy, M. [Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India. (India)] [Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India. (India)

2014-02-15T23:59:59.000Z

277

DOI: 10.1002/chem.201002027 Surface-Enhanced Raman Scattering of Single-and Few-Layer Graphene by  

E-Print Network [OSTI]

DOI: 10.1002/chem.201002027 Surface-Enhanced Raman Scattering of Single- and Few-Layer Graphene*[a] Introduction Raman spectroscopy has been utilized as a powerful tool for the characterization of graphene and any defects in the graphene.[1] A Si substrate with a metal oxide layer of a specific thick- ness has

Kim, Bongsoo

278

THE JOURNAL OF CHEMICAL PHYSICS 135, 184202 (2011) Can stimulated Raman pumping cause large population transfers in  

E-Print Network [OSTI]

THE JOURNAL OF CHEMICAL PHYSICS 135, 184202 (2011) Can stimulated Raman pumping cause large 2011; published online 9 November 2011) When stimulated Raman pumping (SRP) is applied to a stream with the energy difference between the pump and Stokes laser pulses. Using the optical Bloch-Feynman equations, we

Zare, Richard N.

279

785 nm Raman spectroscopy of CVD diamond films P.W. May , J.A. Smith, K.N. Rosser  

E-Print Network [OSTI]

using 785 nm excitation with 1 µm spot size, the Raman spectra from thin polycrystalline diamond films785 nm Raman spectroscopy of CVD diamond films P.W. May , J.A. Smith, K.N. Rosser School is a powerful technique often used to study CVD diamond films, however, very little work has been reported

Bristol, University of

280

Horizontal-Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures  

SciTech Connect (OSTI)

Quantitative data on turbulence variables aloft--above the region of the atmosphere conveniently measured from towers--has been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA’s High Resolution Doppler Lidar (HRDL), which have been shown to be numerically equivalent to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance ?u2 were computed from HRDL measurements of the line-of-sight (LOS) velocity using a technique described in Banta, et al. (2002). The technique was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. It then describes several series of averaging tests that produced the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal velocity variance ?u2. The results show high correlation (0.71-0.97) of the mean U and average wind speed measured by sodar and in-situ instruments, independent of sampling strategies and averaging procedures. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging techniques.

Pichugina, Yelena L.; Banta, Robert M.; Kelley, Neil D.; Jonkman, Bonnie J.; Tucker, Sara C.; Newsom, Rob K.; Brewer, W. A.

2008-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

High-resolution inverse Raman and resonant-wave-mixing spectroscopy  

SciTech Connect (OSTI)

These research activities consist of high-resolution inverse Raman spectroscopy (IRS) and resonant wave-mixing spectroscopy to support the development of nonlinear-optical techniques for temperature and concentration measurements in combustion research. Objectives of this work include development of spectral models of important molecular species needed to perform coherent anti-Stokes Raman spectroscopy (CARS) measurements and the investigation of new nonlinear-optical processes as potential diagnostic techniques. Some of the techniques being investigated include frequency-degenerate and nearly frequency-degenerate resonant four-wave-mixing (DFWM and NDFWM), and resonant multi-wave mixing (RMWM).

Rahn, L.A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

282

Theory of Two-Magnon Raman Scattering in Iron Pnictides and Chalcogenides  

SciTech Connect (OSTI)

Although the parent iron-based pnictides and chalcogenides are itinerant antiferromagnets, the use of local moment picture to understand their magnetic properties is still widespread. We study magnetic Raman scattering from a local moment perspective for various quantum spin models proposed for this new class of superconductors. These models vary greatly in the level of magnetic frustration and show a vastly different two-magnon Raman response. Light scattering by two-magnon excitations thus provides a robust and independent measure of the underlying spin interactions. In accord with other recent experiments, our results indicate that the amount of magnetic frustration in these systems may be small.

Chen, C. C.

2011-08-15T23:59:59.000Z

283

Enhancement of photoluminescence and raman scattering in one-dimensional photonic crystals based on porous silicon  

SciTech Connect (OSTI)

In porous-silicon-based multilayered structures that exhibit the properties of one-dimensional photonic crystals, an increase in the photoluminescence and Raman scattering intensities is observed upon optical excitation at the wavelength 1.064 {mu}m. When the excitation wavelength falls within the edge of the photonic band gap of the structures, a multiple increase (by a factor larger than 400) in the efficiency of Raman scattering is detected. The effect is attributed to partial localization of excitation light and, correspondingly, to the much longer time of interaction of light with the material in the structures.

Gonchar, K. A., E-mail: k.a.gonchar@gmail.com [Moscow State University, Physics Faculty (Russian Federation); Musabek, G. K.; Taurbayev, T. I. [Al Farabi Kazakh National University, Physics Department (Kazakhstan); Timoshenko, V. Yu. [Moscow State University, Physics Faculty (Russian Federation)

2011-05-15T23:59:59.000Z

284

Manipulation of the Raman process via incoherent pump, tunable intensity, and phase control  

E-Print Network [OSTI]

Manipulation of the Raman process via incoherent pump, tunable intensity, and phase control Li-Gang Wang,1,2,3 Sajid Qamar,1 Shi-Yao Zhu,1,2,3 and M. Suhail Zubairy1,4,5 1Centre for Quantum Physics, COMSATS Institute of Information Technology..., Texas 77845, USA 5Texas A&M University at Qatar, P.O. Box 23874, Education City, Doha, Qatar #1;Received 14 May 2007; published 18 March 2008#2; We present a proposal to manipulate the Raman process via incoherent pump, tunable intensity, and phase...

Wang, Li-Gang; Qamar, Sajid; Zhu, Shi-Yao; Zubairy, M. Suhail

2008-01-01T23:59:59.000Z

285

Coherent anti-Stokes Raman microspectroscopy using spectral focusing with glass dispersion  

SciTech Connect (OSTI)

We demonstrate experimentally that coherent anti-Stokes Raman microspectroscopy with high spectral resolution is achieved using femtosecond laser pulses chirped up to a few picoseconds by glass elements of known group-velocity dispersion without significant intensity losses. By simply choosing the length of the glass, the chirp of Stokes and pump pulses is tailored to obtain a spectral resolution given by the Fourier limit of the chirped pulse duration. We show that for chirped pulse durations shorter than or comparable to the Raman coherence time, maximum signal occurs for a pump arriving after the Stokes pulse, a time-ordering effect confirmed by numerical simulations.

Rocha-Mendoza, Israel; Langbein, Wolfgang; Borri, Paola [School of Biosciences and School of Physics and Astronomy, Cardiff University, Museum Avenue, Cardiff CF10 3US (United Kingdom)

2008-11-17T23:59:59.000Z

286

Role of noise operators on two-photon correlations in an extended coherent Raman medium  

E-Print Network [OSTI]

Role of noise operators on two-photon correlations in an extended coherent Raman medium C. H. Raymond Ooi1,2,3,4,* and M. Suhail Zubairy3,5 1Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 Korea 2Max... & Aerospace Engineering, Princeton University, New Jersey 08544, USA 5Texas A&M University at Qatar, Education City, P.O. Box 23874, Doha, Qatar #1;Received 8 January 2007; published 29 May 2007#2; An extended medium driven in a double Raman configuration...

Ooi, C. H. Raymond; Zubairy, M. Suhail.

2007-01-01T23:59:59.000Z

287

382 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 22, NO. 2, FEBRUARY 2004 Effect of a Raman Co-Pump's RIN on the BER  

E-Print Network [OSTI]

382 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 22, NO. 2, FEBRUARY 2004 Effect of a Raman Co-Pump's RIN from a Raman co-pump, on the bit-error rate (BER). We show that a given amount of the transferred RIN spontaneous emission (ASE) noise, than erbium amplifiers. The backward-pumping scheme, where the Raman pump

Lakoba, Taras I.

288

Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave radiometer data are systematically compared to models to quantify and  

E-Print Network [OSTI]

Cloud fraction, liquid and ice water contents derived from long-term radar, lidar, and microwave a systematic evaluation of clouds in forecast models. Clouds and their associated microphysical processes for end users of weather forecasts, who may be interested not only in cloud cover, but in other variables

Hogan, Robin

289

Evaluation of Cloud-Phase Retrieval Methods for SEVIRI on Meteosat-8 Using Ground-Based Lidar and Cloud Radar Data  

E-Print Network [OSTI]

Evaluation of Cloud-Phase Retrieval Methods for SEVIRI on Meteosat-8 Using Ground-Based Lidar and Cloud Radar Data ERWIN L. A. WOLTERS, ROBERT A. ROEBELING, AND ARNOUT J. FEIJT Royal Netherlands 2007) ABSTRACT Three cloud-phase determination algorithms from passive satellite imagers are explored

Stoffelen, Ad

290

A comparison of automated land cover/use classification methods for a Texas bottomland hardwood system using lidar, spot-5, and ancillary data  

E-Print Network [OSTI]

decisions affecting these disappearing systems. SPOT-5 imagery from 2005 was combined with Light Detection and Ranging (LiDAR) data from 2006 and several ancillary datasets to map a portion of the bottomland hardwood system found in the Sulphur River Basin...

Vernon, Zachary Isaac

2009-05-15T23:59:59.000Z

291

SilviLaser 2011, Oct. 16-19, 2011 Hobart, Australia Towards automated and operational forest inventories with T-Lidar  

E-Print Network [OSTI]

inventories with T-Lidar A. Othmani1 , A. Piboule2 , M. Krebs3 , C. Stolz1 and L.F.C. Lew Yan Voon1 1 Cluny, France, michael.krebs@ensam.eu Keywords: terrestrial laser scanning, forest inventory, tree detection, DBH. Abstract Forest inventory automation has become a major issue in forestry. The complexity

Paris-Sud XI, Université de

292

LIDAR Wind Speed Measurement Analysis and Feed-Forward Blade Pitch Control for Load Mitigation in Wind Turbines: January 2010--January 2011  

SciTech Connect (OSTI)

This report examines the accuracy of measurements that rely on Doppler LIDAR systems to determine their applicability to wind turbine feed-forward control systems and discusses feed-forward control system designs that use preview wind measurements. Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feed-forward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. The first half of this report examines the accuracy of different measurement scenarios that rely on coherent continuous-wave or pulsed Doppler LIDAR systems to determine their applicability to feed-forward control. In particular, the impacts of measurement range and angular offset from the wind direction are studied for various wind conditions. A realistic case involving a scanning LIDAR unit mounted in the spinner of a wind turbine is studied in depth with emphasis on choices for scan radius and preview distance. The effects of turbulence parameters on measurement accuracy are studied as well. Continuous-wave and pulsed LIDAR models based on typical commercially available units were used in the studies present in this report. The second half of this report discusses feed-forward control system designs that use preview wind measurements. Combined feedback/feed-forward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent above-rated winds. The feed-forward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Three feed-forward designs are studied: non-causal series expansion, Preview Control, and optimized FIR filter. The input to the feed-forward controller is a measurement of incoming wind speeds that could be provided by LIDAR. Non-causal series expansion and Preview Control methods reduce blade root loads but increase tower bending in simulation results. The optimized FIR filter reduces loads overall, keeps pitch rates low, and maintains rotor speed regulation and power capture, while using imperfect wind measurements provided by the spinning continuous-wave LIDAR model.

Dunne, F.; Simley, E.; Pao, L.Y.

2011-10-01T23:59:59.000Z

293

Detection and quantitative analysis of chemical species in Hanford tank materials using Raman spectroscopy technology: FY94, January 1, 1994--March 31, 1995  

SciTech Connect (OSTI)

This report provides a summary of work completed in FY-94 by FSU to develop and investigate the feasibility of using Raman spectroscopy with Hanford tank waste materials. Raman performance impacts from sample morphology, including the effects of absorption, particle size, density, color and refractive index, are discussed. An algorithm for relative species concentration measurement from Raman data is presented. An Algorithm for applying Raman to tank waste core screening is presented and discussed. A library of absorption and Raman spectra are presented that support this work.

Vickers, T.J.; Mann, C. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry

1995-09-12T23:59:59.000Z

294

Structure in Nascent Carbon Nanotubes Revealed by Spatially Resolved Raman Spectroscopy  

E-Print Network [OSTI]

or filtration [1], supercapacitors [2], composite materials [3,4]. They are mainly prepared by CVD (Chemical1 Structure in Nascent Carbon Nanotubes Revealed by Spatially Resolved Raman Spectroscopy Périne: The understanding of carbon nanotubes (CNT) growth is crucial for the control of their production. In particular

295

Quantitative concentration measurements of creatinine dissolved in water and urine using Raman  

E-Print Network [OSTI]

to the lack of suitable materials with refractive indices lower that of water (n 1.33). Recently, howeverQuantitative concentration measurements of creatinine dissolved in water and urine using Raman in water and in urine. At short integration times, where shot noise is most troublesome, the enhanced

Berger, Andrew J.

296

Development of the Mars microbeam Raman spectrometer (MMRS) Alian Wang,1  

E-Print Network [OSTI]

mineralogy in a planetary exploration. INDEX TERMS: 3672 Mineralogy and Petrology: Planetary mineralogy and petrology (5410); 3694 Mineralogy and Petrology: Instruments and techniques; 3994 Mineral Physics: Raman spectroscopy, Mars in-situ mineralogy, Planetary on-surface mineral identification, Water on Mars

297

Murchison presolar carbon grains of different density fractions: A Raman spectroscopic perspective  

E-Print Network [OSTI]

for inorganic sp2 -bonded carbon. Based on their D/G intensity ratios, those grains were grouped.1), "glassy carbon" (D/G > 1.1), and "unusual sp2 -bonded graphitic car- bon" (with extremely intense 2ndMurchison presolar carbon grains of different density fractions: A Raman spectroscopic perspective

298

Excitonic effects of photoluminescence and resonance Raman intensity of single wall carbon nanotubes  

E-Print Network [OSTI]

1 Excitonic effects of photoluminescence and resonance Raman intensity of single wall carbon been widely used for the optical characterization of single wall carbon nanotubes (SWNTs) since the intensity and energy of PL and RRS depend on the diameter and chirality of SWNTs. The optical absorption

Maruyama, Shigeo

299

INDIAN ACADEMY OF SCIENCES C.V.RamanAvenue,Sadashivanagar,Bangalore560080.  

E-Print Network [OSTI]

INDIAN ACADEMY OF SCIENCES C.V.RamanAvenue,Sadashivanagar,Bangalore560080. Indian Academy of the Academy consist of publication of scientific journals, election of Fellows, organizing scientific meetings, initiatives such as promoting science education,etc. The Academy is looking for a suitable person to fill

Joshi, Yogesh Moreshwar

300

Indian Academy of Sciences C V Raman Avenue, Sadashivanagar, Bangalore 560 080  

E-Print Network [OSTI]

Indian Academy of Sciences C V Raman Avenue, Sadashivanagar, Bangalore 560 080 No. : IASc/ /13 System' The Indian Academy of Sciences is in need of `Multi-point Video Conference System: The Purchase In-charge, Indian Academy of Sciences latest by 30th December 2013 by 15:00 PM. Technical

Joshi, Yogesh Moreshwar

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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.


301

Raman spectroscopy on surfacted ferrofluids in a magnetic field J. E. Weber,1  

E-Print Network [OSTI]

a magnetic excitation with an intensity growing in proportion to the magnetization of the ferrofluid becomes of counteracting in- teractions. On one hand, thermal motion and electrostatic or surfactant-mediated repulsion scatter- ing in general and Raman spectroscopy in particular are a very powerful and sensitive tool

Nabben, Reinhard

302

BARANIDHARAN (BARANI) RAMAN, B.Eng., M.S., Ph.D. Brauer Hall, 2007  

E-Print Network [OSTI]

, and M. Stopfer, "Temporally diverse firing patterns in olfactory receptor neurons underlie spatio microsensors," IEEE Sensors, Special Issue on Sensors for Breath Analysis, Vol. 10, pp. 137-144, January 2010. Raman, and M. Stopfer, "Frequency transitions in odor- evoked neural oscillations," Neuron, Vol. 64, pp

Raman, Barani

303

Raman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond  

E-Print Network [OSTI]

superconductivity at temperatures polycrystalline boron-doped CVD diamond filmsRaman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films P.W. May a,*, W.J. Ludlow a , M. Hannaway a , P.J. Heard b , J

Bristol, University of

304

Raman and Photoluminescence Spectroscopy of Nanocrystalline Diamond Films grown by Hot Filament CVD  

E-Print Network [OSTI]

H4 flow-rate ratio of standard polycrystalline diamond deposition parameters on formationRaman and Photoluminescence Spectroscopy of Nanocrystalline Diamond Films grown by Hot Filament CVD of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia b,c Diamond Research Laboratory, School

Bristol, University of

305

Journal of Crystal Growth 288 (2006) 5356 Spatially resolved photoluminescence and Raman spectroscopy of  

E-Print Network [OSTI]

in a waveguide with a core consisting of GaAs/AlAs short superlattice (SSL) structure using quantum well spectroscopy measurements, where Raman spectra were collected at different depths of the SSL through probing the SSL layer cross-section. SSL-related phonon states were clearly observed for the lower part of the SSL

2006-01-01T23:59:59.000Z

306

hal-00276997,version1-5May2008 Raman spectra of misoriented bilayer graphene  

E-Print Network [OSTI]

hal-00276997,version1-5May2008 Raman spectra of misoriented bilayer graphene P. Poncharal1 , A layer graphene with a bilayer in which the two layers are arbitrarily misoriented. The profiles of the 2 of the electronic structures of single layer graphene and misoriented bilayer graphene. Another new aspect

307

Quasitransient backward Raman amplification of powerful laser pulses in dense plasmas with multicharged ions  

E-Print Network [OSTI]

are found. The calculation, applicable to infrared, ultraviolet, soft x-ray, and x-ray laser pulses, takes technique is also applicable to shorter wavelength laser pulses including x-ray pulses for which CPA cannotQuasitransient backward Raman amplification of powerful laser pulses in dense plasmas

308

Raman spectra of out-of-plane phonons in bilayer graphene  

E-Print Network [OSTI]

The double resonance Raman spectra of the overtone of the out-of-plane tangential optical (oTO) phonon and of combinations of the LO, ZO, and ZA phonons with one another are calculated for bilayer graphene. In the case of ...

Sato, Kentaro

309

Saturation of the Raman amplification by self-phase modulation in silicon nanowaveguides  

E-Print Network [OSTI]

of short pulses in order to project and optimize the performance of future silicon-based data processing to a regime in which sensitivity to FCA is strongly reduced.7-10 However, depending on the pulse energy-off Raman gain is measured in terms of the pump intensity and shows a clear saturation that is attributed

310

Homogeneous Decomposition Mechanisms of Diethylzinc by Raman Spectroscopy and Quantum Chemical Calculations  

E-Print Network [OSTI]

for direct reaction products in an inverted, impinging-jet test reactor coupled to a Raman spectrometer. The homogeneous thermal decomposition of DEZn in N2 carrier was followed in an impinging-jet, up-flow reactor vibrational frequencies of DEZn, as well as anticipated intermediates and products. Comparison of the measured

Anderson, Timothy J.

311

ROTATIONAL AND VIBRATIONAL RAMAN SPECTROSCOPY FOR FLOW FROM AN UNDEREXPANDED JET NOZZLE  

E-Print Network [OSTI]

will be carried out using roational-vibrational Raman line imaging through the axis of the jet exhaust. In this way measurements of the flow field under high pressure, temperature, and velocity can be made without disrupting it. Because of the increasing push...

Bayeh, Alexander

2008-08-19T23:59:59.000Z

312

THE RAMAN SPECTRUM OF MAGNESIUM FLUORIDE By R. S. KRISHNAN and R. S. KATIYAR,  

E-Print Network [OSTI]

627. THE RAMAN SPECTRUM OF MAGNESIUM FLUORIDE By R. S. KRISHNAN and R. S. KATIYAR, Department, NOVEMBRE 1965, I Magnesium fluoride, which occurs in nature as the mineral sellaite, crystallizes spectrum of magnesium fluoride (MgF2) taken with a medium Quartz spectrograph. (b) Its microphotometer

Paris-Sud XI, Université de

313

Spectroscopic Raman Nanometrology of Graphene and Graphene Multilayers on Arbitrary Substrates  

E-Print Network [OSTI]

Spectroscopic Raman Nanometrology of Graphene and Graphene Multilayers on Arbitrary Substrates I to be an effective tool for characterization of graphene and graphene multilayers on the standard Si/SiO2 (300 nm) substrates, which allows one to determine non-destructively the number of the graphene layers and assess

314

High-Sensitivity Raman Spectrometer To Study Pristine and Irradiated Interstellar Ice Analogs  

E-Print Network [OSTI]

to ionizing radiation which produces small quantities of new chemical species within the bulk of the icesHigh-Sensitivity Raman Spectrometer To Study Pristine and Irradiated Interstellar Ice Analogs Chris with low temperature ices relevant to the solar system and interstellar medium. The design is based

Kaiser, Ralf I.

315

Thermal metamorphism in the lesser Himalaya of Nepal determined from Raman spectroscopy of carbonaceous material  

E-Print Network [OSTI]

Thermal metamorphism in the lesser Himalaya of Nepal determined from Raman spectroscopy of central and far-western Nepal, including data from near the MCT zone, where a comparison with conventional on the thermal evolution of the Himalaya in Nepal using the RSCM method. This emblematic geological setting

Avouac, Jean-Philippe

316

Investigation of the Thermal Decomposition of Triethylgallium Using in situ Raman Spectroscopy and DFT Calculations  

E-Print Network [OSTI]

(TEGa) were followed using in situ Raman spectroscopy measurements in an up-flow, cold-wall CVD reactor an design with ss beads to p ure 1. Schem asurements. dy, the gas p ectroscopy i h numerical ons, which w Ex

Anderson, Timothy J.

317

Numerical Procedure to Extract Physical Properties from Raman Scattering Data in a Flow Reactor  

E-Print Network [OSTI]

in an up-flow cold-wall CVD reactor was monitored using in situ Raman spectroscopy. A two uncertainties by removing complicating phenomena or sim- plifying model development. An up-flow cold-wall CVD of the process would be useful, e.g., for optimizing an existing process or designing a new reactor. Accurate

Anderson, Timothy J.

318

Coded Aperture Raman Spectroscopy for Quantitative Measurements of Ethanol in a Tissue Phantom  

E-Print Network [OSTI]

- mard transform spectroscopy'' (HTS).9 Initially, HTS systems were designed to use multiplexing tissue phantom. With 60 mW of excitation power at 808 nm, leave-one-out and blind cross spectroscopy; Multiplexing; Chemometrics. INTRODUCTION Raman spectroscopy is a powerful diagnostic tool

Pitsianis, Nikos P.

319

Layers for Effective Volume Rendering Sundaresan Raman, Oleg Mishchenko, and Roger Crawfis, Member, IEEE Computer Society  

E-Print Network [OSTI]

Layers for Effective Volume Rendering Sundaresan Raman, Oleg Mishchenko, and Roger Crawfis, Member, IEEE Computer Society Abstract--A multi-layer volume rendering framework is presented. The final image is obtained by compositing a number of renderings, each being represented as a separate layer. This layer

Crawfis, Roger

320

Developments in enzyme immobilization and near-infrared Raman spectroscopy with downstream renewable energy applications  

SciTech Connect (OSTI)

This dissertation focuses on techniques for (1) increasing ethanol yields from saccharification and fermentation of cellulose using immobilized cellulase, and (2) the characterization and classification of lignocellulosic feedstocks, and quantification of useful parameters such as the syringyl/guaiacyl (S/G) lignin monomer content using 1064 nm dispersive multichannel Raman spectroscopy and chemometrics.

Lupoi, Jason [Ames Laboratory

2012-08-27T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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.


321

Coherent anti-stokes Raman spectroscopy system for point temperature and major species concentration measurement  

SciTech Connect (OSTI)

The Coherent anti-Stokes Raman Spectroscopy system (CARS) has been developed as a laser-based, advanced, combustion-diagnostic technique to measure temperature and major species concentration. Principles of operation, description of the system and its capabilities, and operational details of this instrument are presented in this report.

Singh, J.P.; Yueh, Fang-Yu

1993-10-01T23:59:59.000Z

322

Rotational and Vibrational Raman Spectroscopy for Thermochemistry Measurements in Supersonic Flames  

E-Print Network [OSTI]

the development of new line imaging diagnostics for thermochemistry measurements in high speed flows. A novel combination of vibrational and rotational Raman scattering is used to measure major species densities (O_2, N_2, CH_4, H_2O,CO_2, CO, & H_2...

Bayeh, Alexander C

2013-05-31T23:59:59.000Z

323

Raman and absorption spectrophotometric studies of selected lanthanide, californium-doped lanthanide, and actinide trihalides in the solid state  

SciTech Connect (OSTI)

The solid-state absorption spectra of Cf(III) ions as a dopant in lanthanide trihalide hosts (LnCl/sub 3/: Ln = Ce, Sm, and Y; LnBr/sub 3/: Ln = Ce, Sm, Tb, and Y; LnI/sub 3/: Ln = Ce and Y) have been recorded. The spectra of Cf(III) have been correlated with the various crystal structures. The phonon Raman spectra and solid-state absorption spectra of PmF/sub 3/, PmCl/sub 3/, PmBr/sub 3/, and two crystal modifications of PmI/sub 3/ have been recorded. Symmetry assignments have been made for the Raman-active bands for these trihalides and also the sesquioxide. The room-temperature absorption spectra have been correlated to crystal field effects. The symmetry assignments of the Raman-active phonon modes have been made based on polarized Raman spectra from single crystals of YF/sub 3/-type orthorhombic TbF/sub 3/ and PuBr/sub 3/-type orthorhombic NdBr/sub 3/. Raman spectra of other isostructural lanthanide compounds have been recorded and compared. Symmetry assignments for these compounds have been made by analogy to the single-crystal assignments. Raman spectra have been obtained and catalogued for a number of actinide compounds. Symmetry assignments have been made for the observed Raman-active phonon bands in this work based on the assignments made for isostructural lanthanide compounds. 29 figs., 22 tabs.

Wilmarth, W.R.

1988-03-01T23:59:59.000Z

324

Analysis of mixing layer heights inferred from radiosonde, wind profiler, airborne lidar, airborne microwave temperature profiler, and in-situ aircraft data during the Texas 2000 air quality study in Houston, TX  

E-Print Network [OSTI]

The mixing layer (ML) heights inferred from radiosondes, wind profilers, airborne lidar, airborne microwave temperature profiler (MTP), and in-situ aircraft data were compared during the Texas 2000 Air Quality Study in the Houston area...

Smith, Christina Lynn

2005-08-29T23:59:59.000Z

325

Multidimensional resonance raman spectroscopy by six-wave mixing in the deep UV  

SciTech Connect (OSTI)

Two-dimensional (2D) resonance Raman spectroscopies hold great potential for uncovering photoinduced relaxation processes in molecules but are not yet widely applied because of technical challenges. Here, we describe a newly developed 2D resonance Raman experiment operational at the third-harmonic of a Titanium-Sapphire laser. High-sensitivity and rapid data acquisition are achieved by combining spectral interferometry with a background-free (six-pulse) laser beam geometry. The third-harmonic laser pulses are generated in a filament produced by the fundamental and second-harmonic pulses in neon gas at pressures up to 35 atm. The capabilities of the setup are demonstrated by probing ground-state wavepacket motions in triiodide. The information provided by the experiment is explored with two different representations of the signal. In one representation, Fourier transforms are carried out with respect to the two experimentally controlled delay times to obtain a 2D Raman spectrum. Further insights are derived in a second representation by dispersing the signal pulse in a spectrometer. It is shown that, as in traditional pump-probe experiments, the six-wave mixing signal spectrum encodes the wavepacket's position by way of the (time-evolving) emission frequency. Anharmonicity additionally induces dynamics in the vibrational resonance frequency. In all cases, the experimental signals are compared to model calculations based on a cumulant expansion approach. This study suggests that multi-dimensional resonance Raman spectroscopies conducted on systems with Franck-Condon active modes are fairly immune to many of the technical issues that challenge off-resonant 2D Raman spectroscopies (e.g., third-order cascades) and photon-echo experiments in the deep UV (e.g., coherence spikes). The development of higher-order nonlinear spectroscopies operational in the deep UV is motivated by studies of biological systems and elementary organic photochemistries.

Molesky, Brian P.; Giokas, Paul G.; Guo, Zhenkun; Moran, Andrew M., E-mail: ammoran@email.unc.edu [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States)

2014-09-21T23:59:59.000Z

326

Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions  

SciTech Connect (OSTI)

The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis suggests that the major element compositions can be determined with root mean square errors ca. 5% (absolute) for SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}(total), MgO, and CaO, and ca. 2% or less for TiO{sub 2}, Cr{sub 2}O{sub 3}, MnO, K{sub 2}O, and Na{sub 2}O. Finally, the Raman experiments have been conducted under supercritical CO{sub 2} involving single-mineral and mixed-mineral samples containing talc, olivine, pyroxenes, feldspars, anhydrite, barite, and siderite. The Raman data have shown that the individual minerals can easily be identified individually or in mixtures.

Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

2010-12-13T23:59:59.000Z

327

Charge Density Waves in Exfoliated Films of van der Waals Materials: Evolution of Raman Spectrum in TiSe2  

E-Print Network [OSTI]

Charge Density Waves in Exfoliated Films of van der Waals Materials: Evolution of Raman Spectrum graphene-like mechanical exfoliation of TiSe2 crystals to prepare a set of films with different thicknesses

328

Multiscalar line measurements in nonisobaric high-pressure underexpanded supersonic jets using rotational-vibrational raman spectroscopy  

E-Print Network [OSTI]

line. In every point, temperature will be measured by examining the Boltzmann decay of the rotational spectrum, while molar fraction will be measured from the vibrational Raman spectrum. The temperature and concentrations will then be combined to obtain...

Cohen, Benjamin Nathan

2009-05-15T23:59:59.000Z

329

Stimulated Raman scattering of laser in a plasma in the presence of a co-propagating electron beam  

SciTech Connect (OSTI)

A relativistic electron beam co-propagating with a high power laser in plasma is shown to add to the growth of the stimulated Raman back scattering of the laser. The growth rate is sensitive to phase matching of electron beam with the plasma wave. In the case of phase mismatch, the growth rate drops by an order. The energy spread of the electron beam significantly reduces the effectiveness of the beam on the stimulated Raman process.

Parashar, J. [Department of Physics, Samrat Ashok Technological Institute, Vidisha, Madhya Pradesh 464001 (India)] [Department of Physics, Samrat Ashok Technological Institute, Vidisha, Madhya Pradesh 464001 (India)

2013-12-15T23:59:59.000Z

330

Studies of ground-state dynamics in isolated species by ionization-detected stimulated Raman techniques  

SciTech Connect (OSTI)

First, the author aims to develop methods of nonlinear Raman spectroscopy for application in studies of sparse samples. Second, the author wishes to apply such methods to structural and dynamical studies of species (molecules, complexes, and clusters) in supersonic molecular beams. In the past year, the author has made progress in several areas. The first pertains to the application of mass-selective ionization-detected stimulated Raman spectroscopies (IDSRS) to the size-specific vibrational spectroscopy of solute-solvent{sub n} clusters. The second involves the application of IDSRS methods to studies of jet-cooled benzene clusters. The third pertains to the use of IDSRS methods in the study of intermolecular vibrational transitions in van der Waals complexes.

Felker, P.M. [Univ. of California, Los Angeles (United States)

1993-12-01T23:59:59.000Z

331

Laser irradiation of carbon nanotube films: Effects and heat dissipation probed by Raman spectroscopy  

SciTech Connect (OSTI)

We investigate the thermal properties of thin films formed by single- and multi-walled carbon nanotubes submitted to laser irradiation using Raman scattering as a probe of both the tube morphology and the local temperature. The nanotubes were submitted to heating/cooling cycles attaining high laser intensities ({approx}1.4 MW/cm{sup 2}) under vacuum and in the presence of an atmosphere, with and without oxygen. We investigate the heat diffusion of the irradiated nanotubes to their surroundings and the effect of laser annealing on their properties. The presence of oxygen during laser irradiation gives rise to an irreversible increase of the Raman efficiency of the carbon nanotubes and to a remarkable increase of the thermal conductivity of multi-walled films. The second effect can be applied to design thermal conductive channels in devices based on carbon nanotube films using laser beams.

Mialichi, J. R.; Brasil, M. J. S. P.; Iikawa, F. [Instituto de Fisica 'Gleb Wataghin,' Unicamp, Campinas, 13083-859 Sao Paulo (Brazil); Verissimo, C.; Moshkalev, S. A. [Centro de Componentes Semicondutores, Unicamp, Campinas, 13083-870 Sao Paulo (Brazil)

2013-07-14T23:59:59.000Z

332

Raman Scattering of Water and Photoluminescence of Pollutants Arising from Solid-Water Interaction  

E-Print Network [OSTI]

Systematic Raman experiments performed on water and water-ethanol samples, stored in different containers (fused silica, polypropylene, soda-lime glass type III) for several hours, have shown that the luminescence contribution to the Raman signal fluctuations is directly related to the container composition. Intensity fluctuations as large as 98%, have been observed in the spectral regions corresponding to the both water intramolecular and intermolecular vibrations, despite the fact that the wavenumbers of the modes remained unchanged. We undoubtedly attribute these fluctuations to a luminescence phenomenon on the basis of : i) the absence of such effect in the anti-Stokes domain, ii) its dependence on the excitation laser wavelength, iii) other relevant photoluminescence experiments. This luminescence is attributed to pollutants at ultra-low concentration coming from the different containers.

Vallée, P; Ghomi, M; Jouanne, M; Vall\\'{e}e, Philippe; Lafait, Jacques; Ghomi, Mahmoud; Jouanne, Michel

2003-01-01T23:59:59.000Z

333

Surface-enhanced Raman medical probes and system for disease diagnosis and drug testing  

DOE Patents [OSTI]

A probe for a surface-enhanced Raman scattering spectrometer includes a member of optically transmissive material for receiving the excitation radiation from a laser and for carrying the radiation emitted from a specimen to a detector. An end of the member for placing against the specimen has a coating that produces surface enhancement of the specimen during Raman scattering spectroscopic analysis. Specifically the coating is formed by a first layer of microparticles on the member and a metal layer over the first layer. The first layer may form a microstructure surface over which a metal layer is applied. Alternatively the coating may be a material containing microparticles of a metal. An optional layer of a material may be applied to the metal layer to concentrate onto the probe compounds of analytical interest onto the probe. 39 figs.

Vo-Dinh, T.

1999-01-26T23:59:59.000Z

334

The effect of external magnetic field on the Raman peaks in manganites  

SciTech Connect (OSTI)

We report here a microscopic theoretical model study exhibiting the effect of external magnetic field on the Raman excitation peaks in the CMR manganite system. The Hamiltonian consists of Jahn-Teller (J-T) distortion in e{sub g} band, the double exchange interaction and the Heisenberg spin-spin interaction. Further the phonons are coupled to e{sub g} band electrons, J-T distorted e{sub g} band and the double exchange interaction. The Raman spectral intensity is calculated from the imaginary part of the phonon Green function. The spectra exhibits three peaks besides a very weak high energy peak. The magnetic field effect on these peaks are reported.

Sahu, A. K., E-mail: ajitsahu@seemantaengg.ac.in [Seemanta Engineering College, Jharpokharia, Mayurbhanj-757086, Odisha (India); Rout, G. C. [School of Applied Sciences (Physics), KIIT University, Bhubaneswar-7561024 (India)

2014-04-24T23:59:59.000Z

335

Stimulated Raman Scattering and Nonlinear Focusing of High-Power Laser Beams Propagating in Water  

E-Print Network [OSTI]

The physical processes associated with propagation of a high-power (power > critical power for self-focusing) laser beam in water include nonlinear focusing, stimulated Raman scattering (SRS), optical breakdown and plasma formation. The interplay between nonlinear focusing and SRS is analyzed for cases where a significant portion of the pump power is channeled into the Stokes wave. Propagation simulations and an analytical model demonstrate that the Stokes wave can re-focus the pump wave after the power in the latter falls below the critical power. It is shown that this novel focusing mechanism is distinct from cross-phase focusing. While discussed here in the context of propagation in water, the gain-focusing phenomenon is general to any medium supporting nonlinear focusing and stimulated forward Raman scattering.

Hafizi, B; Penano, J R; Gordon, D F; Jones, T G; Helle, M H; Kaganovich, D

2015-01-01T23:59:59.000Z

336

Application of Raman spectroscopy to identification and sorting of post-consumer plastics for recycling  

DOE Patents [OSTI]

A high accuracy rapid system for sorting a plurality of waste products by polymer type. The invention involves the application of Raman spectroscopy and complex identification techniques to identify and sort post-consumer plastics for recycling. The invention reads information unique to the molecular structure of the materials to be sorted to identify their chemical compositions and uses rapid high volume sorting techniques to sort them into product streams at commercially viable throughput rates. The system employs a laser diode (20) for irradiating the material sample (10), a spectrograph (50) is used to determine the Raman spectrum of the material sample (10) and a microprocessor based controller (70) is employed to identify the polymer type of the material sample (10).

Sommer, Edward J. (Nashville, TN); Rich, John T. (Lebanon, TN)

2001-01-01T23:59:59.000Z

337

Enhanced Raman sideband cooling of caesium atoms in a vapour-loaded magneto-optical trap  

E-Print Network [OSTI]

We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loading magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load $1.5 \\times 10^7$ atoms into the Raman lattice with a detuning of -15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 $\\mu$K to 1.7 $\\mu$K within 12 ms and the number of obtained atoms is about $1.2 \\times 10^7$. A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system.

Li, Y; Feng, G; Nute, J; Piano, S; Hackermuller, L; Ma, J; Xiao, L; Jia, S

2015-01-01T23:59:59.000Z

338

UV-Raman spectroscopy on nanotubes@zeolite Wavelength dependence Ab initio calculations  

E-Print Network [OSTI]

UV-Raman spectroscopy on nanotubes@zeolite June, 2005 Wavelength dependence Ab initio calculations 4 Energy (eV) 0 2 4 Energy (eV) (arb.units) (2,1) (4,1) (5,0) (3,3) (4,2)(4,0) (2,2) (3,0) 1Institut involving the peak at 650 cm-1. Nanotubes grown inside the channels of zeolite crystals are constrained

Nabben, Reinhard

339

Entangled valence electron-hole dynamics revealed by stimulated attosecond x-ray Raman scattering  

SciTech Connect (OSTI)

We show that broadband x-ray pulses can create wavepackets of valence electrons and holes localized in the vicinity of a selected atom (nitrogen, oxygen or sulfur in cysteine) by resonant stimulated Raman scattering. The subsequent dynamics reveals highly correlated motions of entangled electrons and hole quasiparticles. This information goes beyond the time-dependent total charge density derived from x-ray diffraction.

Healion, Daniel; Zhang, Yu; Biggs, Jason D.; Govind, Niranjan; Mukamel, Shaul

2012-09-06T23:59:59.000Z

340

Understanding the application of Raman spectroscopy to the detection of traces of life  

E-Print Network [OSTI]

may be translational, rotational, vibrational, or electronic in nature. For a vibrational mode to be Raman active, a change in po- larizability as the molecule vibrates is needed. Molecules consist of a nuclear structure surrounded by a complex field... to struc- tural changes that perturb translational symmetry in car- bonaceous materials, which thus makes this a powerful method by which to characterize carbon structure (e.g., Dresselhaus and Dresselhaus, 1982 and references therein). 230 MARSHALL ET AL...

Marshall, Craig P.; Edwards, Howell G.M.; Jehlicka, Jan

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Femtosecond Raman induced polarization spectroscopy studies of coherent rotational dynamics in molecular fluids  

SciTech Connect (OSTI)

We develop a polarization-sensitive femtosecond pump probe technique, Raman induced polarization spectroscopy (RIPS), to study coherent rotation in molecular fluids. By observing the collisional dephasing of the coherently prepared rotational states, we are able to extract information concerning the effects of molecular interactions on the rotational motion. The technique is quite sensitive because of the zero background detection method, and is also versatile due to its nonresonant nature.

Morgen, M.M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; [Lawrence Berkeley National Lab., CA (United States)

1997-05-01T23:59:59.000Z

342

Molecular cavity optomechanics: a theory of plasmon-enhanced Raman scattering  

E-Print Network [OSTI]

The exceptional enhancement of Raman scattering cross-section by localized plasmonic resonances in the near-field of metallic surfaces, nanoparticles or tips has enabled spectrocopic fingerprinting of single-molecules and is widely used in material, chemical and biomedical analysis. Contrasting with this overwhelming practical success, conventional theories based on electromagnetic "hot spots" and electronic or chemical effects cannot account for all experimental observations. Here we present a novel theory of plasmon-enhanced Raman scattering by mapping the problem to cavity optomechanics. Using FEM and DFT simulations we calculate the optomechanical vacuum coupling rate between individual molecules and hot spots of metallic dimers. We find that dynamical backaction of the plasmon on the vibrational mode can lead to amplification of molecular vibrations under blue-detuned laser excitation, thereby revealing an enhancement mechanism not contemplated be- fore. The optomechanical theory provides a quantitative framework for the calculation of enhanced cross-sections, recovers known results, and enables the design of novel systems that leverage dynamical backaction to achieve additional, mode-selective enhancement. It yields a new understanding of plasmon-enhanced Raman scattering and opens a route to molecular quantum optomechanics.

Philippe Roelli; Christophe Galland; Nicolas Piro; Tobias J. Kippenberg

2014-07-06T23:59:59.000Z

343

CuAl{sub 2} revisited: Composition, crystal structure, chemical bonding, compressibility and Raman spectroscopy  

SciTech Connect (OSTI)

The structure of CuAl{sub 2} is usually described as a framework of base condensed tetragonal antiprisms [CuAl{sub 8/4}]. The appropriate symmetry governed periodic nodal surface (PNS) divides the space of the structure into two labyrinths. All atoms are located in one labyrinth, whereas the second labyrinth seems to be 'empty'. The bonding of the CuAl{sub 2} structure was analyzed by the electron localization function (ELF), crystal orbital Hamiltonian population (COHP) analysis and Raman spectroscopy. From the ELF representation it is seen, that the 'empty' labyrinth is in fact the place of important covalent interactions. ELF, COHP in combination with high-pressure X-ray diffraction and Raman spectroscopy show that the CuAl{sub 2} structure is described best as a network built of interpenetrating graphite-like nets of three-bonded aluminum atoms with the copper atoms inside the tetragonal-antiprismatic cavities. - Graphical abstract: Atomic interactions in the crystal structure of the intermetallic compound CuAl{sub 2}: Three-bonded aluminum atoms form interpenetrating graphite-like nets. The copper atoms are located in the channels of aluminum network by means of three-center bonds. The bonding model is in agreement with the result of polarized Raman spectroscopy and high-pressure X-ray powder diffraction.

Grin, Yuri [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany)]. E-mail: grin@cpfs.mpg.de; Wagner, Frank R. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Armbruester, Marc [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Kohout, Miroslav [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Leithe-Jasper, Andreas [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Schwarz, Ulrich [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 01187 Dresden (Germany); Wedig, Ulrich [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstr. 1, 70569 Stuttgart (Germany); Georg von Schnering, Hans [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstr. 1, 70569 Stuttgart (Germany)

2006-06-15T23:59:59.000Z

344

Horizontal Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures  

SciTech Connect (OSTI)

Quantitative data on turbulence variables aloft--above the region of the atmosphere conveniently measured from towers--have been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA's high-resolution Doppler lidar (HRDL), which have been shown to be approximately equal to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance {sigma}2u were computed from HRDL measurements of the line-of-sight (LOS) velocity using a method described by Banta et al., which uses an elevation (vertical slice) scanning technique. The method was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. The results for the mean U and mean wind speed measured by sodar and in situ instruments for all nights of LLLJP show high correlation (0.71-0.97), independent of sampling strategies and averaging procedures, and correlation coefficients consistently >0.9 for four high-wind nights, when the low-level jet speeds exceeded 15 m s{sup -1} at some time during the night. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging parameters. Several series of averaging tests are described, to find the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal-velocity variance {sigma}{sup 2}{sub u}. Because of the nonstationarity of the SBL data, the best results were obtained when the velocity data were first averaged over intervals of 1 min, and then further averaged over 3-15 consecutive 1-min intervals, with best results for the 10- and 15-min averaging periods. For these cases, correlation coefficients exceeded 0.9. As a part of the analysis, Eulerian integral time scales ({tau}) were estimated for the four high-wind nights. Time series of {tau} through each night indicated erratic behavior consistent with the nonstationarity. Histograms of {tau} showed a mode at 4-5 s, but frequent occurrences of larger {tau} values, mostly between 10 and 100 s.

Pichugina, Y. L.; Banta, R. M.; Kelley, N. D.; Jonkman, B. J.; Tucker, S. C.; Newsom, R. K.; Brewer, W. A.

2008-08-01T23:59:59.000Z

345

E-Print Network 3.0 - aerosol main physical Sample Search Results  

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

AND INTEGRAL AEROSOL PROPERTIES RETRIEVAL FROM RAMAN LIDAR DATA USING PRINCIPLE COMPONENT ANALYSIS Summary: retrievals of physical aerosol parameters from ground-based and...

346

Combined Quantum Chemical/Raman Spectroscopic Analyses of Li+ Cation Solvation: Cyclic Carbonate Solvents - Ethylene Carbonate and Propylene Earbonate  

SciTech Connect (OSTI)

Combined computational/Raman spectroscopic analyses of ethylene carbonate (EC) and propylene carbonate (PC) solvation interactions with lithium salts are reported. It is proposed that previously reported Raman analyses of (EC)n-LiX mixtures have utilized faulty assumptions. In the present studies, density functional theory (DFT) calculations have provided corrections in terms of both the scaling factors for the solvent's Raman band intensity variations and information about band overlap. By accounting for these factors, the solvation numbers obtained from two different EC solvent bands are in excellent agreement with one another. The same analysis for PC, however, was found to be quite challenging. Commercially available PC is a racemic mixture of (S)- and (R)-PC isomers. Based upon the quantum chemistry calculations, each of these solvent isomers may exist as multiple conformers due to a low energy barrier for ring inversion, making deconvolution of the Raman bands daunting and inherently prone to significant error. Thus, Raman spectroscopy is able to accurately determine the extent of the EC...Li+ cation solvation interactions using the provided methodology, but a similar analysis of PC...Li+ cation solvation results in a significant underestimation of the actual solvation numbers.

Allen, Joshua L.; Borodin, Oleg; Seo, D. M.; Henderson, Wesley A.

2014-12-01T23:59:59.000Z

347

Note: Deep ultraviolet Raman spectrograph with the laser excitation line down to 177.3 nm and its application  

SciTech Connect (OSTI)

Deep UV Raman spectrograph with the laser excitation line down to 177.3 nm was developed in this laboratory. An ellipsoidal mirror and a dispersed-subtractive triple monochromator were used to collect and disperse Raman light, respectively. The triple monochromator was arranged in a triangular configuration with only six mirrors used. 177.3 nm laser excited Raman spectrum with cut-off wavenumber down to 200 cm{sup ?1} and spectral resolution of 8.0 cm{sup ?1} can be obtained under the condition of high purity N{sub 2} purging. With the C–C ? bond in Teflon selectively excited by the 177.3 nm laser, resonance Raman spectrum of Teflon with good quality was recorded on the home-built instrument and the ?-?{sup *} transition of C–C bond was studied. The result demonstrates that deep UV Raman spectrograph is powerful for studying the systems with electronic transition located in the deep UV region.

Jin, Shaoqing [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China) [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Fan, Fengtao; Guo, Meiling; Zhang, Ying; Feng, Zhaochi, E-mail: zcfeng@dicp.ac.cn, E-mail: canli@dicp.ac.cn; Li, Can, E-mail: zcfeng@dicp.ac.cn, E-mail: canli@dicp.ac.cn [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)] [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

2014-04-15T23:59:59.000Z

348

Detection of surface carbon and hydrocarbons in hot spot regions of niobium superconducting rf cavities by Raman spectroscopy  

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

Raman microscopy/spectroscopy measurements are presented on high purity niobium (Nb) samples, including pieces from hot spot regions of a tested superconducting rf cavity that exhibit a high density of etch pits. Measured spectra are compared with density functional theory calculations of Raman-active, vibrational modes of possible surface Nb-O and Nb-H complexes. The Raman spectra inside particularly rough pits in all Nb samples show clear differences from surrounding areas, exhibiting enhanced intensity and sharp peaks. While some of the sharp peaks are consistent with calculated NbH and NbH2 modes, there is better overall agreement with C-H modes in chain-type hydrocarbons. Other spectra reveal two broader peaks attributed to amorphous carbon. Niobium foils annealed to >2000°C in high vacuum develop identical Raman peaks when subjected to cold working. Regions with enhanced C and O have also been found by SEM/EDX spectroscopy in the hot spot samples and cold-worked foils, corroborating the Raman results. Such regions with high concentrations of impurities are expected to suppress the local superconductivity and this may explain the correlation between hot spots in superconducting rf (SRF) cavities and the observation of a high density of surface pits. The origin of localized high carbon and hydrocarbon regions is unclear at present but it is suggested that particular processing steps in SRF cavity fabrication may be responsible.

Cao, C.; Ford, D.; Bishnoi, S.; Proslier, T.; Albee, B.; Hommerding, E.; Korczakowski, A.; Cooley, L.; Ciovati, G.; Zasadzinski, J. F.

2013-06-01T23:59:59.000Z

349

Airborne Multiwavelength High-Spectral-Resolution Lidar (HSRL-2) Observations During TCAP 2012: Vertical Proles of Optical and Microphysical Properties of a Smoke/Urban Haze Plume Over the Northeastern Coast of the US  

SciTech Connect (OSTI)

We present rst measurements with the rst airborne multiwavelength High-Spectral Resolution Lidar (HSRL-2), developed by NASA Langley Research Center. The instrument was operated during the Department of Energy (DOE) Two-Column Aerosol Project (TCAP) in July 2012. We observed out ow of urban haze and fresh biomass burning smoke from the East Coast of the US out over the West Atlantic Ocean. Lidar ratios at 355 and 532 nm were ... sr indicating moderately absorbing aerosols. Extinctionrelated Angstrom exponents were 1.5{2 pointing at comparably small particles. Our novel automated, unsupervised data inversion algorithm retrieves particle e*ective radii of approximately 0.2 *m, which is in agreement with the large Angstrom exponents. We nd reasonable agreement to particle size parameters obtained from situ measurements carried out with the DOE G-1 aircraft that ew during the lidar observations.

Muller, Detlef; Hostetler, Chris A.; Ferrare, R. A.; Burton, S. P.; Chemyakin, Eduard; Kolgotin, A.; Hair, John; Cook, A. L.; Harper, David; Rogers, R. R.; Hare, Rich; Cleckner, Craig; Obland, Michael; Tomlinson, Jason M.; Berg, Larry K.; Schmid, Beat

2014-10-10T23:59:59.000Z

350

Combined raman and IR fiber-based sensor for gas detection  

DOE Patents [OSTI]

A double-pass fiber-optic based spectroscopic gas sensor delivers Raman excitation light and infrared light to a hollow structure, such as a hollow fiber waveguide, that contains a gas sample of interest. A retro-reflector is placed at the end of this hollow structure to send the light back through the waveguide where the light is detected at the same end as the light source. This double pass retro reflector design increases the interaction path length of the light and the gas sample, and also reduces the form factor of the hollow structure.

Carter, Jerry C; Chan, James W; Trebes, James E; Angel, Stanley M; Mizaikoff, Boris

2014-06-24T23:59:59.000Z

351

Demonstration of triple pump coherent anti-Stokes Raman scattering in a jet diffusion flame  

E-Print Network [OSTI]

. A. Theory 1. Coherent anti-Stokes Raman scattering basics B. Dual-pump and triple-pump CARS processes 1. Dual-pump CARS 2. Triple pump CARS C. Thermometry and species detection EXPERIMENTAL APPARATUS A. Initial experimental system 1. Laser.... Laser Alignment and Performance I . Nd: YAG laser 2. Narrow band dye laser (ND6000) alignment 3. Broad-band dye laser alignment B. Triple-pump CARS set-up 1. CARS phase-matching alignment 2. Diffusion flame burner C. Results I. Results from first...

Velur Natarajan, Viswanathan

2002-01-01T23:59:59.000Z

352

Glucose concentration measured by the hybrid coherent anti-Stokes Raman-scattering technique  

E-Print Network [OSTI]

PHYSICAL REVIEW A 81, 013813 (2010) Glucose concentration measured by the hybrid coherent anti-Stokes Raman-scattering technique Xi Wang, Aihua Zhang, Miaochan Zhi, Alexei V. Sokolov, and George R. Welch Department of Physics and Institute... is controlled by two translation stages (DS1 and DS2 in Fig. 1). They overlap at their focuses either in a crossing-beam configuration (Figs. 3, 4, and 7) as in Fig. 1 1050-2947/2010/81(1)/013813(6) 013813-1 ?2010 The American Physical Society WANG, ZHANG...

Wang, Xi; Zhang, Aihua; Zhi, Miaochan; Sokolov, Alexei V.; Welch, George R.

2010-01-01T23:59:59.000Z

353

[Laser flash photolysis, EPR and Raman studies of liquids at elevated pressures  

SciTech Connect (OSTI)

The proposed research will solve a number of analytical chemical problems in solutions with measurement techniques that benefit from the use of elevated hydrostatic pressures: stopped-flow spectrophotometry (Gd[sup 3+] + L(ligand), [RuL[sub 5]H[sub 2]O][sup 2+], laser flash photolysis of Mo(CO)[sub 6] + L, flash photolysis of binuclear metalloproteins), EPR spectroscopy (Gd[sup 3+] ion-exchanged into ETS-10 and ETAS-10 molecular sieves), laser flash photolysis kinetic studies of Mo(CO)[sub 6]-2,2'-bipyridine, and electrochemical studies of metalloporphyrins using resonance Raman spectroscopy.

Eyring, E.M.

1992-01-01T23:59:59.000Z

354

[Laser flash photolysis, EPR and Raman studies of liquids at elevated pressures  

SciTech Connect (OSTI)

The proposed research will solve a number of analytical chemical problems in solutions with measurement techniques that benefit from the use of elevated hydrostatic pressures: stopped-flow spectrophotometry (Gd{sup 3+} + L(ligand), [RuL{sub 5}H{sub 2}O]{sup 2+}, laser flash photolysis of Mo(CO){sub 6} + L, flash photolysis of binuclear metalloproteins), EPR spectroscopy (Gd{sup 3+} ion-exchanged into ETS-10 and ETAS-10 molecular sieves), laser flash photolysis kinetic studies of Mo(CO){sub 6}-2,2`-bipyridine, and electrochemical studies of metalloporphyrins using resonance Raman spectroscopy.

Eyring, E.M.

1992-10-01T23:59:59.000Z

355

Two-dimensional stimulated resonance Raman spectroscopy of molecules with broadband x-ray pulses  

SciTech Connect (OSTI)

Expressions for the two-dimensional stimulated x-ray Raman spectroscopy (2D-SXRS) signal obtained using attosecond x-ray pulses are derived. The 1D- and 2D-SXRS signals are calculated for trans-N-methyl acetamide (NMA) with broad bandwidth (181 as, 14.2 eV FWHM) pulses tuned to the oxygen and nitrogen K-edges. Crosspeaks in 2D signals reveal electronic Franck-Condon overlaps between valence orbitals and relaxed orbitals in the presence of the core-hole.

Biggs, Jason D.; Zhang Yu; Healion, Daniel; Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States)

2012-05-07T23:59:59.000Z

356

Numerical investigation of mid-infrared Raman soliton source generation in endless single mode fluoride fibers  

SciTech Connect (OSTI)

We numerically investigate Raman soliton generation in a fluoride photonic crystal fiber (PCF) pumped by 1.93 ?m femtosecond fiber lasers in order to get widely tunable laser source in the mid-infrared region. The simulated results show that a continuously tunable range (1.93???3.95??m) over 2000?nm is achieved in 1-m-long fluoride PCF pumped by a 1.93??m femtosecond fiber laser with a pulse width of 200 fs. The power conversion efficiency is also calculated and the maximum efficiency can be up to 84.27%.

Liu, Lai; Qin, Guan-Shi, E-mail: qings@jlu.edu.cn; Tian, Qi-jun; Zhao, Dan; Qin, Wei-Ping, E-mail: wpqin@jlu.edu.cn [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

2014-04-28T23:59:59.000Z

357

Production of entanglement in Raman three-level systems using feedback  

E-Print Network [OSTI]

We examine the theoretical limits of the generation of entanglement in a damped coupled ion-cavity system using jump-based feedback. Using Raman transitions to produce entanglement between ground states reduces the necessary feedback bandwidth, but does not improve the overall effect of the spontaneous emission on the final entanglement. We find that the fidelity of the resulting entanglement will be limited by the asymmetries produced by vibrations in the trap, but that the concurrence remains above 0.88 for realistic ion trap sizes.

R. N. Stevenson; A. R. R. Carvalho; J. J. Hope

2010-01-10T23:59:59.000Z

358

Microwave-stimulated Raman adiabatic passage in a Bose-Einstein condensate on an atom chip  

E-Print Network [OSTI]

We report the achievement of stimulated Raman adiabatic passage (STIRAP) in the microwave frequency range between internal states of a Bose-Einstein condensate (BEC) magnetically trapped in the vicinity of an atom chip. The STIRAP protocol used in this experiment is robust to external perturbations as it is an adiabatic transfer, and power-efficient as it involves only resonant (or quasi-resonant) processes. Taking into account the effect of losses and collisions in a non-linear Bloch equations model, we show that the maximum transfer efficiency is obtained for non-zero values of the one- and two-photon detunings, which is confirmed quantitatively by our experimental measurements.

Dupont-Nivet, Matthieu; Laudat, Théo; Westbrook, Christoph I; Schwartz, Sylvain

2015-01-01T23:59:59.000Z

359

Effects of noise and parameter deviations in a bichromatic Raman white light cavity  

E-Print Network [OSTI]

PHYSICAL REVIEW A 81, 033826 (2010) Effects of noise and parameter deviations in a bichromatic Raman white light cavity Qingqing Sun,1 M. Selim Shahriar,2 and M. Suhail Zubairy1 1Department of Physics and Institute of Quantum Studies, Texas A... coefficient ?. At the central frequency we have n ?= 1+ 1 2 ? ? = 1+ 1 2 (?M1 +M2)#6; #6;2 + 2 , (2) ? ?= ?0 2c ? ?? = ? ?0 2c (M1 +M2) #6;2 + 2 , (3) 1050-2947/2010/81(3)/033826(4) 033826-1 ?2010 The American Physical Society SUN...

Sun, Qingqing; Shahriar, M. Selim; Zubairy, M. Suhail

2010-01-01T23:59:59.000Z

360

Entangled radiation via a Raman-driven quantum-beat laser  

E-Print Network [OSTI]

with 1 and 2 being the cavity decay rates of modes 1 and 2, respectively. Here, #11;11 and #11;22 are the linear gain coefficients, whereas #11;12 and #11;21 are the phase-sensitive cross-coupling coefficients that are generated due to the atomic... coherence produced between the levels #8;b1#7; and #8;b2#7; via the two-photon Raman process using two strong driving fields. Explicit expressions for the coefficients #11;11, #11;12, #11;21, and #11;22 in Eq. #1;7#2; are given in Appendix B. The phase...

Qamar, Sajid; Al-Amri, M.; Qamar, Shahid; Zubairy, M. Suhail

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Methods and systems for Raman and optical cross-interrogation in flow-through silicon membranes  

DOE Patents [OSTI]

Cross-interrogating photonic detection systems and methods are shown. A flow through photonic crystal membrane with a surface enhanced Raman scattering (SERS) substrate is provided with pores which are distributed along multiple regions. The pores of one region have walls to which a first type of target specific anchor can be attached, while pores of another region have walls to which a second type of target specific anchor can be attached. An optical arrangement out-of-plane to the SERS substrate is also provided for enhanced sensitivity and identification of target organisms.

Bond, Tiziana C.; Letant, Sonia E.

2014-09-09T23:59:59.000Z

362

Raman scattering of rare earth sesquioxide Ho{sub 2}O{sub 3}: A pressure and temperature dependent study  

SciTech Connect (OSTI)

Pressure and temperature dependent Raman scattering studies on Ho{sub 2}O{sub 3} have been carried out to investigate the structural transition and the anharmonic behavior of the phonons. Ho{sub 2}O{sub 3} undergoes a transition from cubic to monoclinic phase above 15.5?GPa, which is partially reversible on decompression. The anharmonic behavior of the phonon modes of Ho{sub 2}O{sub 3} from 80?K to 440?K has been investigated. We find an anomalous line-width change with temperature. The mode Grüneisen parameter of bulk Ho{sub 2}O{sub 3} was estimated from high pressure Raman investigation up to 29?GPa. Furthermore, the anharmonic components were calculated from the temperature dependent Raman scattering.

Pandey, Sugandha Dogra; Samanta, K.; Singh, Jasveer; Sharma, Nita Dilawar; Bandyopadhyay, A. K. [Pressure and Vacuum Standards, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)

2014-10-07T23:59:59.000Z

363

Raman-assisted DPP-BOTDA sensor employing Simplex coding with sub-meter scale spatial resolution over 93 km standard SMF  

E-Print Network [OSTI]

Raman-assisted DPP-BOTDA sensor employing Simplex coding with sub-meter scale spatial resolution technique is combined with bi-directional Raman amplification and Simplex coding to achieve sub-meter successfully employed to attain sub-meter spatial resolution [1-3], although typically exhibiting limited

Thévenaz, Jacques

364

Magnetic sublevel specific stimulated Raman pumping of molecular H2 Sarah Cureton-Chinn, Peter B. Kelly, and Matthew P. Augustinea)  

E-Print Network [OSTI]

Magnetic sublevel specific stimulated Raman pumping of molecular H2 Sarah Cureton-Chinn, Peter B of the X 1 g ,v 1,J 1 state of molecular H2 using stimulated Raman pumping with circularly polarized light for the v 0 and v 1 states combined with their depolarization ratios measured as a function of pumping light

Augustine, Mathew P.

365

W. N. WANGet al.: Laser Raman Studies of Polycrystalline and A-Diamond Films 255 phys. stat. sol. (a) 154,255 (1996)  

E-Print Network [OSTI]

W. N. WANGet al.: Laser Raman Studies of Polycrystalline and A-Diamond Films 255 phys. stat. sol, Transducer Systems Division, Wotton-under-Edge4)(d) Laser Raman Studies of Polycrystalline and Amorphic Diamond Films W. N. WANG(a), N. A. FOX(a), P. W. MAY(b), M. P. KNAPPER(b), G. MEADEN(c), P. G. PARTRIDGE

Bristol, University of

1996-01-01T23:59:59.000Z

366

Vision 20/20: The role of Raman spectroscopy in early stage cancer detection and feasibility for application in radiation therapy response assessment  

SciTech Connect (OSTI)

Raman spectroscopy is an optical technique capable of identifying chemical constituents of a sample by their unique set of molecular vibrations. Research on the applicability of Raman spectroscopy in the differentiation of cancerous versus normal tissues has been ongoing for many years, and has yielded successful results in the context of prostate, breast, brain, skin, and head and neck cancers as well as pediatric tumors. Recently, much effort has been invested on developing noninvasive “Raman” probes to provide real-time diagnosis of potentially cancerous tumors. In this regard, it is feasible that the Raman technique might one day be used to provide rapid, minimally invasive real-time diagnosis of tumors in patients. Raman spectroscopy is relatively new to the field of radiation therapy. Recent work involving cell lines has shown that the Raman technique is able to identify proteins and other markers affected by radiation therapy. Although this work is preliminary, one could ask whether or not the Raman technique might be used to identify molecular markers that predict radiation response. This paper provides a brief review of Raman spectroscopic investigations in cancer detection, benefits and limitations of this method, advances in instrument development, and also preliminary studies related to the application of this technology in radiation therapy response assessment.

Devpura, Suneetha, E-mail: sdevpur1@hfhs.org; Barton, Kenneth N.; Brown, Stephen L.; Siddiqui, Farzan; Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan 48202 (United States)] [Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan 48202 (United States); Palyvoda, Olena [College of Engineering, Wayne State University, Detroit, Michigan 48202 (United States)] [College of Engineering, Wayne State University, Detroit, Michigan 48202 (United States); Kalkanis, Steven [Department of Neurosurgery, Henry Ford Hospital, Detroit, Michigan 48202 (United States)] [Department of Neurosurgery, Henry Ford Hospital, Detroit, Michigan 48202 (United States); Naik, Vaman M. [Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128 (United States)] [Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128 (United States); Naik, Ratna [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)] [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)

2014-05-15T23:59:59.000Z

367

An Epi-Detected Coherent Anti-Stokes Raman Scattering (E-CARS) Microscope with High Spectral Resolution and High Sensitivity  

E-Print Network [OSTI]

LETTERS An Epi-Detected Coherent Anti-Stokes Raman Scattering (E-CARS) Microscope with High-detected coherent anti-Stokes Raman scattering (E-CARS) microscope that uses two synchronized picosecond pulse (CARS) microscopy provides a unique approach to imaging chemical and biological samples by using

Xie, Xiaoliang Sunney

368

Light-induced oxygen-ordering dynamics in ,,Y,Pr...Ba2Cu3O6.7: A Raman spectroscopy and Monte Carlo study  

E-Print Network [OSTI]

Light-induced oxygen-ordering dynamics in ,,Y,Pr...Ba2Cu3O6.7: A Raman spectroscopy and Monte Carlo energy barrier which impedes oxygen movement in the plane unless the oxygen atoms are excited by light for oxygen reordering in the chain plane being at the origin of Raman photobleaching and related effects. DOI

Nabben, Reinhard

369

Crystallinity and compositional changes in carbonated apatites: Evidence from {sup 31}P solid-state NMR, Raman, and AFM analysis  

SciTech Connect (OSTI)

Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and {sup 31}P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse {sup 31}P NMR linewidth and inverse Raman PO{sub 4}{sup 3?}?{sub 1} bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO{sub 3}{sup 2?} range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the {sup 31}P NMR chemical shift frequency and the Raman phosphate ?{sub 1} band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. - Graphical abstract: Carbonated apatite shows an abrupt change in spectral (NMR, Raman) and morphological (AFM) properties at a composition of about one carbonate substitution per unit cell. Display Omitted - Highlights: • Crystallinity (XRD), particle size (AFM) of carbonated apatites and bone mineral. • Linear relationships among crystallinity, {sup 31}P NMR and Raman inverse bandwidths. • Low and high carbonated apatites use different charge-balancing ion-loss mechanism.

McElderry, John-David P.; Zhu, Peizhi [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Mroue, Kamal H. [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Xu, Jiadi [Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Pavan, Barbara [Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Fang, Ming [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T. [School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Holl, Mark M.Banaszak [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Tecklenburg, Mary M.J., E-mail: mary.tecklenburg@cmich.edu [Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Ramamoorthy, Ayyalusamy [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Morris, Michael D. [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States)

2013-10-15T23:59:59.000Z

370

Controlling rotational state distributions using two-pulse stimulated Raman excitation  

SciTech Connect (OSTI)

The femtosecond stimulated Raman process is a versatile technique to excite rotational states in molecules. We demonstrate control over the rotational state population in a sample of NO molecules by varying the time delay between two identical laser pulses. The product of the rotational state distribution is probed by a 1+1 resonance-enhanced multiphoton ionization scheme and simulated quantum mechanically. There is good agreement between theoretical and experimental results. The product in selected quantum states shows an oscillatory dependence on the time delay. Spectral analysis reveals rotational transition energies and the presence of multiple Raman steps. We show that the relative strength of these frequency components can be related to excitation pathways with predominant {delta}J=2 transitions toward higher rotational states. The initial step from J=1/2 involves either {delta}J=1 or {delta}J=2. We find that one can discriminate between two excitation ladders. The results demonstrate the coherent effects of tailoring the shape of an ultrashort excitation pulse.

Meijer, A. S.; Zhang, Y.; Parker, D. H.; Zande, W. J. van der; Gijsbertsen, A.; Vrakking, M. J. J. [Institute of Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, NL-6500 GL Nijmegen (Netherlands); FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam (Netherlands)

2007-08-15T23:59:59.000Z

371

Growth process of microcrystalline silicon studied by combined photoluminescence and Raman investigations  

SciTech Connect (OSTI)

Plasma enhanced chemical vapor deposition of silicon on glass substrates leads to formation of silicon amorphous films with partial crystallization of nano-grains in the amorphous matrix. We studied the transition of amorphous to microcrystalline silicon during such deposition. Formation of silicon nano-grains was detected by means of photoluminescence and Raman spectroscopy. The crystalline fraction and the mean size of the nano-grains were estimated by the position and the intensity of the peaks in the Raman spectrum. We showed that the fraction of crystalline silicon in the layers and the size of the nano-grains are strongly dependent on the growth conditions. The photoluminescence spectra exhibit distinct features related to recombination in the amorphous and in the crystalline phases. A significant narrowing of the photoluminescence peak related to the amorphous phase with increasing crystalline fraction indicates a structural modification in the amorphous silicon. It suggests an ordering process occurring before the start of the actual crystallization. A peak at about 1.4 eV was associated with isolated nano-crystalline grains within the amorphous matrix. A correlation between the peak energy and grain size was found, indicating effects of carrier quantum confinement. The experimental results confirm the established theoretical models for growth of microcrystalline silicon films.

Klossek, A.; Mankovics, D.; Ratzke, M. [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany)] [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany); Arguirov, T.; Kittler, M. [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany) [Brandenburg University of Technology, Konrad-Wachsmann-Allee 1, D-03046 Cottbus (Germany); IHP Microelectronics, Im Technologiepark 25, D-15236 Frankfurt (Oder) (Germany); Kirner, S.; Gabriel, O.; Stannowski, B.; Schlatmann, R. [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany)] [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany); Friedrich, F. [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany) [Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Helmholtz-Zentrum Berlin, Berlin (Germany); Department of Semiconductor Devices, Technische Universität Berlin, Sekr. E2, Einsteinufer 19, D-10587 Berlin (Germany)

2013-12-14T23:59:59.000Z

372

Sorption Mechanisms of Antibiotic Cephapirin onto Quartz and Feldspar by Raman Spectroscopy  

SciTech Connect (OSTI)

Raman spectroscopy was used to investigate the sorption mechanisms of cephapirin (CHP), a veterinary antibiotic, onto quartz (SiO2) and feldspar (KAlSi3O8) at different pH values. Depending on the charge and surface properties of the mineral, different reaction mechanisms including electrostatic attraction, monodentate and bidentate complexation were found to be responsible for CHP sorption. The zwitterion (CHPo) adsorbs to a quartz(+) surface by electrostatic attraction of the carboxylate anion group ( COO-) at a low pH, but adsorbs to a quartz(-) surface through electrostatic attraction of the pyridinium cation and possibly COO- bridge complexes at relatively higher pH conditions. CHP- bonds to a quartz(-) surface by bidentate complexation between one oxygen of COO- and oxygen from the carbonyl (C=O) of the acetoxymethyl group. On a feldspar surface of mixed charge, CHPo forms monodentate complexes between C=O as well as COO- bridging complexes or electrostatically attached to localized edge (hydr)oxy-Al surfaces. CHP- adsorbs to feldspar(-) through monodentate C=O complexation, and similar mechanisms may operate for the sorption of other cephalosporins. This research demonstrates, for the first time, that Raman spectroscopic techniques can be effective for evaluating the sorption processes and mechanisms of cephalosporin antibiotics even at relatively low sorbed concentrations (97-120 ?mol/kg).

Peterson, Jonathan [Hope College; Wang, Wei [ORNL; Gu, Baohua [ORNL

2009-01-01T23:59:59.000Z

373

Raman Analysis of Perrhenate and Pertechnetate in Alkali Salts and Borosilicate Glasses  

SciTech Connect (OSTI)

Sodium borosilicate glasses containing various concentrations of rhenium or technetium were fabricated, and their vibrational spectra studied using a Raman microscope. Spectra were interpreted with reference to new high resolution measurements of alkali pertechnetates and perrhenates NaReO4, KReO4, NaTcO4, and KTcO4. At low concentrations of ReO4- or TcO4-, glass spectra show weak peaks superimposed on a dominant spectrum of glass characteristic of silicate and borate network vibrations. At high concentrations, sharp peaks characteristic of crystal field splitting and C4h symmetry dominate the spectra of glasses, indicating alkali nearby tetrahedral Re or Tc. Often peaks indicative of both the K and Na pertechnetates/ perrhenates are evident in the Raman spectrum, with the latter being favored at high additions of the source chemical, since Na is more prevalent in the glass and ion exchange takes place. These results have significance to immobilization of nuclear waste containing radioactive 99Tc in glass for ultimate disposal.

Gassman, Paul L.; McCloy, John S.; Soderquist, Chuck Z.; Schweiger, Michael J.

2014-01-03T23:59:59.000Z

374

Schumann-Runge resonance Raman scattering of O sub 2 : A rotationally resolved excitation profile study  

SciTech Connect (OSTI)

Rotationally resolved resonance Raman spectra and excitation profiles of O{sub 2} excited with narrow-band radiation tunable throughout the {nu}{prime} = 5 absorption band of the Schumann-Runge (SR) region (190-192 nm) are reported. The pressure dependence and scattering polarization unambiguously identify all the observed resonant emission intensity as Raman scattering (both resonant and off-resonant), not resonance fluorescence. This characterization is in contrast to the description of the resonant emission of the SR absorption bands offered in recent laser-excited studies. Excitation profile analysis determines rotationally specific lifetimes of the {nu}{prime} = 5 level. A homogeneous line width of 2.05 {plus minus} 0.10 cm{sup {minus}1} is determined for the rotational levels of this vibronic band. Within experimental uncertainty, this line width/lifetime is independent of the rotational angular momentum of the resonant predissociative rovibronic levels of the {nu}{prime} = 5 band. This value is in excellent agreement with the results of the most recent SR absorption contour analysis but is not in quantitative agreement with the most recent theoretical modeling of the rovibronic dynamics of the SR absorption bands.

Zhang, Y.P.; Ziegler, L.D. (Northeastern Univ., Boston, MA (USA))

1989-09-07T23:59:59.000Z

375

Raman gain from waveguides inscribed in KGd,,WO4...2 by high repetition rate femtosecond laser  

E-Print Network [OSTI]

-order nonlinear susceptibility, high ther- mal conductivity, and strong Raman conversion properties. KGW has potential for enhanced non- linear device performance through longer interaction lengths with high amorphous glasses8 and crystalline materials such as lithium niobate,9 quartz,10 Ti:sapphire,11 and KY WO4 2

376

TIME-RESOLVED RAMAN SPECTROSCOPY OF MARS ANALOG MINERALS AND ORGANICS. J. Blacksberg1 Y. Maruyama1  

E-Print Network [OSTI]

1 , E. Alerstam1 , C. Cochrane1 , G.R.Rossman2 , S. Shkolyar3 , J. Farmer3 , 1 Jet Propulsion, California 91125, grr@gps.caltech.edu. 3 School of Earth and Space Exploration, Arizona State University are identified, Raman spectroscopy has the potential to map out minerals on the grain scale and potentially find

Rossman. George R.

377

Raman and conductivity studies of boron-doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films  

E-Print Network [OSTI]

-like conductivity. A complication is that polycrystalline boron-doped CVD diamond films possess grain boundariesRaman and conductivity studies of boron-doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films P.W. May a,, W.J. Ludlow a , M. Hannaway a , P.J. Heard b , J

Bristol, University of

378

Intensities of the Raman-active modes in single and multiwall nanotubes S. Reich and C. Thomsen  

E-Print Network [OSTI]

of recent experiments on aligned nanotubes we calculate the relative intensities for the high-energy modes of the nanotubes and on the excitation energy. As was shown by Milnera et al.3 the radial breathing modeIntensities of the Raman-active modes in single and multiwall nanotubes S. Reich and C. Thomsen

Nabben, Reinhard

379

Analysis of polyethylene wear debris using micro-Raman spectroscopy: A report on the presence of beta-carotene  

E-Print Network [OSTI]

Analysis of polyethylene wear debris using micro-Raman spectroscopy: A report on the presence- high molecular weight polyethylene wear debris isolated from revised knee replacements. The novel the chemical nature of individual, retrieved polyethylene particles. The analysis revealed the presence

Hahn, David W.

380

Fiber optic cone penetrometer raman probe for in situ chemical characterization of the Hanford underground waste tanks  

SciTech Connect (OSTI)

A field hardened fiber optic Raman probe has been developed for cone penetrometer deployment in the Hanford underground chemical waste storage tanks. The corrosive chemical environment of the tanks, as well as Hanford specific deployment parameters, provide unique challenges for the design of an optical probe.

Kyle, K.R.; Brown, S.B.

1997-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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

Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion in the Primary Visual Photoproduct  

E-Print Network [OSTI]

Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion modes and their relation to energy storage in the primary photoproduct. Low-temperature (77 K) resonance interactions of the 9- and 13-methyl groups with surrounding residues. This distortion stores light energy

Chang, Belinda

382

Extended Near-Infrared Resonance Raman Investigations of an Organic Mixed-Valence System: Diazatetracyclodiene Radical Cation  

E-Print Network [OSTI]

Extended Near-Infrared Resonance Raman Investigations of an Organic Mixed-Valence System near-infrared region show that six modes are coupled to the intramolecular charge-transfer transition transfer (IVCT) absorption bands in the red to near- infrared region of the spectrum, which are, at least

383

March 15, 2001 / Vol. 26, No. 6 / OPTICS LETTERS 361 Raman-excited spin coherences in nitrogen-vacancy  

E-Print Network [OSTI]

March 15, 2001 / Vol. 26, No. 6 / OPTICS LETTERS 361 Raman-excited spin coherences in nitrogen-vacancy coherences were experimentally observed in nitrogen-vacancy (N-V) diamond color centers by means we chose to use nitrogen-vacancy (N-V) color centers9 in diamond because they have a large optical

Shahriar, Selim

384

Depth-resolved confocal micro-Raman spectroscopy for characterizing GaN-based light emitting diode structures  

SciTech Connect (OSTI)

In this work, we demonstrate that depth-resolved confocal micro-Raman spectroscopy can be used to characterize the active layer of GaN-based LEDs. By taking the depth compression effect due to refraction index mismatch into account, the axial profiles of Raman peak intensities from the GaN capping layer toward the sapphire substrate can correctly match the LED structural dimension and allow the identification of unique Raman feature originated from the 0.3 ?m thick active layer of the studied LED. The strain variation in different sample depths can also be quantified by measuring the Raman shift of GaN A{sub 1}(LO) and E{sub 2}(high) phonon peaks. The capability of identifying the phonon structure of buried LED active layer and depth-resolving the strain distribution of LED structure makes this technique a potential optical and remote tool for in operando investigation of the electronic and structural properties of nitride-based LEDs.

Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming, E-mail: ymchang@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China)] [Center for Condensed Matter Sciences, National Taiwan University, 10617 Taipei, Taiwan (China); Chang, Chiao-Yun; Huang, Huei-Min; Lu, Tien-Chang [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)] [Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan (China)

2013-11-15T23:59:59.000Z

385

58 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 53, NO. 1, FEBRUARY 2004 Multichannel Raman Gas Analyzer: The Data  

E-Print Network [OSTI]

with the green laser source previously used and reported in a related article. Index Terms--Air-pollution, data Raman Gas Analyzer: The Data Acquisition and Control System. Measurement Improvement With Blue Laser Albrecht, and Nikiforos G. Theofanous Abstract--In this paper, the data acquisition and control system

Athens, University of

386

The Ability of MM5 to Simulate Ice Clouds: Systematic Comparison between Simulated and Measured Fluxes and Lidar/Radar Profiles at SIRTA Atmospheric Observatory  

SciTech Connect (OSTI)

Ice clouds play a major role in the radiative energy budget of the Earth-atmosphere system (Liou 1986). Their radiative effect is governed primarily by the equilibrium between their albedo and greenhouse effects. Both macrophysical and microphysical properties of ice clouds regulate this equilibrium. For quantifying the effect of these clouds onto climate and weather systems, they must be properly characterized in atmospheric models. In this paper we use remote-sensing measurements from the SIRTA ground based atmospheric observatory (Site Instrumental de Recherche par Teledetection Atmospherique, http://sirta.lmd.polytechnique.fr). Lidar and radar observations taken over 18 months are used, in order to gain statistical confidence in the model evaluation. Along this period of time, 62 days are selected for study because they contain parts of ice clouds. We use the ''model to observations'' approach by simulating lidar and radar signals from MM5 outputs. Other more classical variables such as shortwave and longwave radiative fluxes are also used. Four microphysical schemes, among which that proposed by Reisner et al. (1998) with original or modified parameterizations of particle terminal fall velocities (Zurovac-Jevtic and Zhang 2003, Heymsfield and Donner 1990), and the simplified Dudhia (1989) scheme are evaluated in this study.

Chiriaco, M.; Vautard, R.; Chepfer, H.; Haeffelin, M.; Wanherdrick, Y.; Morille, Y.; Protat, A.; Dudhia, J.

2005-03-18T23:59:59.000Z

387

A novel micro-Raman technique to detect and characterize 4H-SiC stacking faults  

SciTech Connect (OSTI)

A novel Micro-Raman technique was designed and used to detect extended defects in 4H-SiC homoepitaxy. The technique uses above band-gap high-power laser densities to induce a local increase of free carriers in undoped epitaxies (n?Raman mode. The Raman shift of the LO phonon-plasmon-coupled mode (LOPC) increases as the free carrier density increases. Crystallographic defects lead to scattering or recombination of the free carriers which results in a loss of coupling with the LOPC, and in a reduction of the Raman shift. Given that the LO phonon-plasmon coupling is obtained thanks to the free carriers generated by the high injection level induced by the laser, we named this technique induced-LOPC (i-LOPC). This technique allows the simultaneous determination of both the carrier lifetime and carrier mobility. Taking advantage of the modifications on the carrier lifetime induced by extended defects, we were able to determine the spatial morphology of stacking faults; the obtained morphologies were found to be in excellent agreement with those provided by standard photoluminescence techniques. The results show that the detection of defects via i-LOPC spectroscopy is totally independent from the stacking fault photoluminescence signals that cover a large energy range up to 0.7?eV, thus allowing for a single-scan simultaneous determination of any kind of stacking fault. Combining the i-LOPC method with the analysis of the transverse optical mode, the micro-Raman characterization can determine the most important properties of unintentionally doped film, including the stress status of the wafer, lattice impurities (point defects, polytype inclusions) and a detailed analysis of crystallographic defects, with a high spectral and spatial resolution.

Piluso, N., E-mail: nicolo.piluso@imm.cnr.it; Camarda, M.; La Via, F. [IMM-CNR, stradale primo sole, 50, 95121 Catania (Italy)

2014-10-28T23:59:59.000Z

388

Subpicosecond time-resolved Raman studies of nonequilibrium excitations in wurtzite GaN  

SciTech Connect (OSTI)

Non-equilibrium electron distributions as well as phonon dynamics in wurtzite GaN have been measured by subpicosecond time-resolved Raman spectroscopy. The experimental results have demonstrated that for electron densities n {ge} 5 {times} 10{sup 17} cm{sup {minus}3}, the non-equilibrium electron distributions in wurtzite GaN can be very well described by Fermi-Dirac distribution functions with the temperature of electrons substantially higher than that of the lattice. The population relaxation time of longitudinal optical phonons was directly measured to be {tau} {approx_equal} 5 {+-} 1 ps at T = 25 K. The experimental results on the temperature dependence of the lifetime of longitudinal optical phonons suggest that the primary decay channels for these phonons are the decay into (1) one transverse optical phonon and one high energy, longitudinal or transverse acoustical phonons; and (2) one transverse optical phonon and one E{sub 2} phonon.

Tsen, K.T.; Ferry, D.K. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics and Astronomy; Joshi, R.P. [Old Dominion Univ., Norfolk, VA (United States). Dept. of Electrical Engineering; Botchkarev, A.; Sverdlov, B.; Salvador, A.; Morkoc, H. [Univ. of Illinois, Urbana, IL (United States). Coordinated Science Lab.

1997-12-31T23:59:59.000Z

389

Raman spectra of aligned carbon micro-coils and their impedance characteristics under loads  

SciTech Connect (OSTI)

Scanning and transmission electron microscopy were used to characterize the morphology of the carbon microcoils (CMCs). The Raman spectra showed that CMCs had local regular structure as I{sub D}/I{sub G}?=?0.841. Then, aligned CMCs/silicone–rubber composites (5?×?5?×?1 mm{sup 3}) were fabricated by coating of silicone rubber on the CMCs. Their alternating current impedance characteristics were measured as a function of applied load and the pressure sensitivity was discussed. The results showed that the impedance decreased as the increasing applied load, and the sample with less CMCs owned high pressure sensitivity, which indicated a novel composite film could act as an alternative of tactile sensor.

Tao, Wang; Yabo, Zhu, E-mail: zhuyabo@163.com; Heliang, Fan; Zhicheng, Ju; Lei, Chen; Zhengyuan, Wang [School of Materials Science and Engineering, China University of Mining and Technology, Xu Zhou, Jiangsu 221116 (China)

2014-02-21T23:59:59.000Z

390

Final Technical Report "Study of Efficiency of Raman Backscattering Amplification in Plasma"  

SciTech Connect (OSTI)

General : Our major scientific achievements in Raman Backscattering (RBS) amplification and compression of short laser pulses in plasma. The laser system based on RBS steps in where the current technology of chirped pulse amplification (CPA) (extremely successful in developing ultra-short and ultra-intense laser pulses in last 2 decades) becomes difficult and very expensive to apply. Good base for such RBS laser was created by our recent experiments, which were supported by GPS grants. The main objective of the present grant was: improvement efficiency of energy transfer from pump to seed. The results surpassed our expectations; we improved the efficiency of energy transfer from pump to seed by a factor of 6 compared to the best of our previous results and amplified seed pulse compressed down to about 50 fsec.

Suckewer, Szymon

2014-03-31T23:59:59.000Z

391

Storage and Manipulation of Light Using a Raman Gradient Echo Process  

E-Print Network [OSTI]

The Gradient Echo Memory (GEM) scheme has potential to be a suitable protocol for storage and retrieval of optical quantum information. In this paper, we review the properties of the $\\Lambda$-GEM method that stores information in the ground states of three-level atomic ensembles via Raman coupling. The scheme is versatile in that it can store and re-sequence multiple pulses of light. To date, this scheme has been implemented using warm rubidium gas cells. There are different phenomena that can influence the performance of these atomic systems. We investigate the impact of atomic motion and four-wave mixing and present experiments that show how parasitic four-wave mixing can be mitigated. We also use the memory to demonstrate preservation of pulse shape and the backward retrieval of pulses.

Hosseini, M; Campbell, G T; Lam, P K; Buchler, B C

2012-01-01T23:59:59.000Z

392

Reactive ion etching-assisted surface-enhanced Raman scattering measurements on the single nanoparticle level  

SciTech Connect (OSTI)

Single-nanoparticle surface-enhanced Raman scattering (SERS) measurement is of essential importance for both fundamental research and practical applications. In this work, we develop a class of single-particle SERS approaches, i.e., reactive ion etching (RIE)-assisted SERS measurements correlated with scanning electron microscopy (SEM) strategy (RIE/SERS/SEM), enabling precise and high-resolution identification of single gold nanoparticle (AuNP) in facile and reliable manners. By using AuNP-coated silicon wafer and quartz glass slide as models, we further employ the developed RIE/SERS/SEM method for interrogating the relationship between SERS substrates and enhancement factor (EF) on the single particle level. Together with theoretical calculation using an established finite-difference-time-domain (FDTD) method, we demonstrate silicon wafer as superior SERS substrates, facilitating improvement of EF values.

Wang, Si-Yi; Jiang, Xiang-Xu; Wei, Xin-Pan; Lee, Shuit-Tong, E-mail: apannale@suda.edu.cn, E-mail: yaohe@suda.edu.cn; He, Yao, E-mail: apannale@suda.edu.cn, E-mail: yaohe@suda.edu.cn [Institute of Functional Nano and Soft Materials - FUNSOM, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, and Devices Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China); Xu, Ting-Ting [Institute of Functional Nano and Soft Materials - FUNSOM, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, and Devices Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, Jiangsu 215123 (China); Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong, China and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong (China)

2014-06-16T23:59:59.000Z

393

Dissecting X-Ray Raman Resonances Using Four-Wave Mixing  

SciTech Connect (OSTI)

The stimulated x-ray Raman signal has been calculated for the amino acid cysteine using broadband (FWHM ?14.2eV, 128 as) pulses tuned to the nitrogen K-edge. Peaks correspond to those valence excited states and reveal electronic Frank-Condon overlaps between canonical valence orbitals and relaxed orbitals in the presence of the core hole. The coupling between excited states with valence- and core-holes is further explored using a coherent, wave-vector matched photon echo technique, where it is possible to eliminate stimulated emission and excited-state absorption by taking the waiting time to be longer the lifetime of the core hole (? 7:1 fs for nitrogen).

Biggs, Jason D.; Zhang, Yu; Healion, Daniel; Govind, Niranjan; Mukamel, Shaul

2013-03-13T23:59:59.000Z

394

Rabi Waves and Peculiarities of Raman Scattering in Carbon Nanotubes, Produced by High Energy Ion Beam Modification of Diamond Single Crystals  

E-Print Network [OSTI]

QED-model for multichain coupled qubit system, proposed in \\cite{Part1}, was confirmed by Raman scattering studies of carbon zigzag-shaped nanotubes, produced by high energy ion beam modification of natural diamond single crystals. New quantum optics phenomenon - Rabi waves - has been experimentally identified for the first time. Raman spectra in perfect quasi-1D carbon nanotubes are quite different in comparison with well known Raman spectra in 2D carbon nanotubes of larger diameter. They characterized by vibronic mode of Su-Schriffer-Heeger $\\sigma$-polaron lattice and its revival part in frequency representation, which is the consequence of Rabi wave packet formation.

Dmitry Yearchuck; Alla Dovlatova

2011-03-06T23:59:59.000Z

395

Using Radar, Lidar, and Radiometer measurements to Classify Cloud Type and Study Middle-Level Cloud Properties  

SciTech Connect (OSTI)

The project is mainly focused on the characterization of cloud macrophysical and microphysical properties, especially for mixed-phased clouds and middle level ice clouds by combining radar, lidar, and radiometer measurements available from the ACRF sites. First, an advanced mixed-phase cloud retrieval algorithm will be developed to cover all mixed-phase clouds observed at the ACRF NSA site. The algorithm will be applied to the ACRF NSA observations to generate a long-term arctic mixed-phase cloud product for model validations and arctic mixed-phase cloud processes studies. To improve the representation of arctic mixed-phase clouds in GCMs, an advanced understanding of mixed-phase cloud processes is needed. By combining retrieved mixed-phase cloud microphysical properties with in situ data and large-scale meteorological data, the project aim to better understand the generations of ice crystals in supercooled water clouds, the maintenance mechanisms of the arctic mixed-phase clouds, and their connections with large-scale dynamics. The project will try to develop a new retrieval algorithm to study more complex mixed-phase clouds observed at the ACRF SGP site. Compared with optically thin ice clouds, optically thick middle level ice clouds are less studied because of limited available tools. The project will develop a new two wavelength radar technique for optically thick ice cloud study at SGP site by combining the MMCR with the W-band radar measurements. With this new algorithm, the SGP site will have a better capability to study all ice clouds. Another area of the proposal is to generate long-term cloud type classification product for the multiple ACRF sites. The cloud type classification product will not only facilitates the generation of the integrated cloud product by applying different retrieval algorithms to different types of clouds operationally, but will also support other research to better understand cloud properties and to validate model simulations. The ultimate goal is to improve our cloud classification algorithm into a VAP.

Wang, Zhien

2010-06-29T23:59:59.000Z

396

Demonstrated Wavelength Portability of Raman Reference Data for Explosives and Chemical Detection  

SciTech Connect (OSTI)

As Raman spectroscopy continues to evolve, questions arise as to the portability of Raman data: dispersive versus Fourier transform, wavelength calibration, intensity calibration, and in particular the frequency of the excitation laser. While concerns about fluorescence arise in the visible or ultraviolet, most modern (portable) systems use near-infrared excitation lasers, and many of these are relatively close in wavelength. We have investigated the possibility of porting reference data sets from one NIR wavelength system to another. We have constructed a reference library consisting of 145 spectra, including 20 explosives, as well as sundry other compounds and materials using a 1064 nm spectrometer. These data were used as a reference library to evaluate the same 145 compounds whose experimental spectra were recorded using a second 785 nm spectrometer. In 128 cases of 145 (or 88.3% including 20/20 for the explosives) the compounds were correctly identified with a mean 'hit score' of 954 of 1000. Adding in criteria for when to declare a correct match versus when to declare uncertainty, the approach was able to correctly categorize 134 out of 145 spectra, giving a 92.4% accuracy. For the few that were incorrectly identified, either the matched spectra were spectroscopically similar to the target or the 785 nm signal was degraded due to fluorescence. The results indicate that imported data recorded at a different NIR wavelength can be successfully used as reference libraries, but key issues must be addressed: The reference data must be of equal or higher resolution, the systems require rigorous wavelength calibration, and wavelength-dependent intensity response should be accounted for in the different systems.

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

2012-04-17T23:59:59.000Z

397

High-pressure behavior of amorphous selenium from ultrasonic measurements and Raman spectroscopy  

SciTech Connect (OSTI)

The high-pressure behavior of melt-quenched amorphous selenium (a-Se) has been investigated via ultrasonic measurements and Raman scattering at room temperature. The ultrasonic measurements were conducted on a-Se in a multi-anvil apparatus with two different sample assemblies at pressures of up to 4.5 and 4.8?GPa. We discovered that similar kinks occur in the slopes of the pressure dependence characteristics of the travel time and the sound velocity in both shear and longitudinal waves in the 2.0–2.5?GPa range. These kinks are independent of the sample assemblies, indicating an intrinsic transformation of the a-Se. Additionally, we deduced the pressure-volume relationship of a-Se from the sound velocity characteristics using the Birch–Murnaghan equation of state, and the results agreed well with those of previous reports. In situ high-pressure Raman scattering measurements of a-Se were conducted in a diamond anvil cell with an 830?nm excitation line up to a pressure of 4.3?GPa. We found that the characteristic band of a-Se at ?250?cm{sup ?1} experienced a smooth shift to a lower frequency with pressure, but a sharp slope change in the band intensity versus pressure occurred near 2.5?GPa. The results of X-ray diffraction and differential scanning calorimetry measurements indicate that the samples remain in their amorphous states after decompression. Thus, we proposed that the abnormal compression behavior of a-Se in the 2.0–2.5?GPa range can be attributed to pressure-induced local atomic reconfiguration, implying an amorphous-amorphous transition of the elementary selenium.

He, Z.; Liu, X. R.; Hong, S. M., E-mail: hpswjtu@gmail.com, E-mail: smhong@home.swjtu.edu.cn [Laboratory of High Pressure Physics, Southwest Jiaotong University, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Chengdu 610031 (China); Wang, Z. G. [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China); Zhu, H. Y. [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Peng, J. P. [School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China)

2014-07-07T23:59:59.000Z

398

Doubly resonant Raman electron paramagnetic transitions of Cr{sup 3+} in ruby (Al{sub 2}O{sub 3}:Cr{sup 3+}).  

SciTech Connect (OSTI)

We report the Raman electron paramagnetic resonance (EPR) of Cr{sup 3+} in ruby (Al{sub 2}O{sub 3}:Cr{sup 3+}) in the {sup 4}A{sub 2} (ground) and E{sup -} (excited) states of its well-known R{sub 1} emission line. Using tunable dye laser excitation within the range of the Zeeman components of R{sub 1}, we observe highly selective doubly resonant enhancements of the Raman EPR lines. The double resonances confirm the assignments of the Raman EPR lines, and they underscore the simultaneous occurrence of both 'in resonance' and 'out resonance' as visualized in the Kramers-Heisenberg quantum-mechanical picture of inelastic light scattering. The g factors of the {sup 4}A{sub 2} and E{sup -} states are consistent with the observed magnetic field dependence of the Raman EPR shifts. Through the interplay of Raman effect and the sharp Zeeman components of R{sub 1}, the results provide clear insights into the underlying microscopic mechanism of these resonant Raman EPR spectra of ruby.

Lu, X.; Venugopalan, S.; Kim, H.; Grimsditch, M.; Rodriguez, S.; Ramdas, A. K.; Materials Science Division; Purdue Univ.; State Univ. of New York at Binghamton; Sogang Univ.

2009-06-01T23:59:59.000Z

399

Structural and Raman scattering study of Ni-doped CoFe{sub 2}O{sub 4}  

SciTech Connect (OSTI)

Raman scattering measurements were made on polycrystalline CoFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} ferrites as prepared by solid-state reaction route. Rietveld refined X-ray diffraction pattern confirmed the formation of single-phase and both of the samples perfectly indexed in cubic spinel structure with Fd3m space group. Slight reduction in the lattice parameter of Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} has been observed as compared to CoFe{sub 2}O{sub 4}. From Raman scattering spectra, a shoulder like feature has been observed in both of the compounds reveals that octahedral site is occupied by Co, Ni and Fe ions and tetrahedral site is occupied by only Fe ion.

Kumar, Ashwini, E-mail: vdinesh33@rediffmail.com; Dar, Mashkoor A., E-mail: vdinesh33@rediffmail.com; Sharma, Poorva, E-mail: vdinesh33@rediffmail.com; Varshney, Dinesh, E-mail: vdinesh33@rediffmail.com [School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road Campus, Indore-452001 (India)

2014-04-24T23:59:59.000Z

400

Raman spectra and magnetization of all-ferromagnetic superlattices grown on (110) oriented SrTiO{sub 3}  

SciTech Connect (OSTI)

Superlattices consist of two ferromagnets La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO) and SrRuO{sub 3} (SRO) were grown in (110)-orientation on SrTiO{sub 3} (STO) substrates. The x-ray diffraction and Raman spectra of these superlattices show the presence of in-plane compressive strain and orthorhombic structure of less than 4 u.c. thick LSMO spacer, respectively. Magnetic measurements reveal several features including reduced magnetization, enhanced coercivity, antiferromagnetic coupling, and switching from antiferromagnetic to ferromagnetic coupling with magnetic field orientations. These magnetic properties are explained by the observed orthorhombic structure of spacer LSMO in Raman scattering which occurs due to the modification in the stereochemistry of Mn at the interfaces of SRO and LSMO.

Behera, B. C.; Ravindra, A. V.; Padhan, P. [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Prellier, W. [Laboratoire CRISMAT, CNRS UMR 6508, ENSICAEN, 6 Bd du Marehal Juin, F-14050 Caen Cedex (France)

2014-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" from the National Library of EnergyBeta (NLEBeta).
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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

Test of Equivalence Principle at $10^{-8}$ Level by a Dual-species Double-diffraction Raman Atom Interferometer  

E-Print Network [OSTI]

We report an improved test of the weak equivalence principle by using a simultaneous $^{85}$Rb-$^{87}$Rb dual-species atom interferometer. We propose and implement a four-wave double-diffraction Raman transition scheme for the interferometer, and demonstrate its ability in suppressing common-mode phase noise of Raman lasers after their frequencies and intensity ratios are optimized. The statistical uncertainty of the experimental data for E\\"{o}tv\\"{o}s parameter $\\eta$ is $0.8\\times10^{-8}$ at 3200 s. With various systematic errors corrected the final value is $\\eta=(2.8\\pm3.0)\\times10^{-8}$. The major uncertainty is attributed to the Coriolis effect.

Zhou, Lin; Tang, Biao; Chen, Xi; Gao, Fen; Peng, Wencui; Duan, Weitao; Zhong, Jiaqi; Xiong, Zongyuan; Wang, Jin; Zhang, Yuanzhong; Zhan, Mingsheng

2015-01-01T23:59:59.000Z

402

Graphene-based textured surface by pulsed laser deposition as a robust platform for surface enhanced Raman scattering applications  

SciTech Connect (OSTI)

We have developed a surface enhanced Raman scattering (SERS)-active substrate based on gold nanoparticles-decorated few-layer (fl) graphene grown by pulsed laser deposition. Diamond-Like Carbon film has been converted to fl-graphene after thermal annealing at low temperature. The formation of fl-graphene was confirmed by Raman spectroscopy, and surface morphology was highlighted by scanning electron microscopy. We found that textured fl-graphene film with nanoscale roughness was highly beneficial for SERS detection. Rhodamine 6G and p-aminothiophenol proposed as test molecules were detected with high sensitivity. The detection at low concentration of deltamethrin, an active molecule of a commercial pesticide was further demonstrated.

Tite, T.; Donnet, C.; Loir, A.-S.; Reynaud, S.; Michalon, J.-Y.; Vocanson, F.; Garrelie, F., E-mail: florence.garrelie@univ-st-etienne.fr [Université de Lyon, F-42023 Saint-Etienne (France); CNRS, UMR 5516, Laboratoire Hubert Curien, F-42000 Saint-Etienne (France); and Université de Saint-Etienne, Jean Monnet, F-42000 Saint-Etienne (France)

2014-01-27T23:59:59.000Z

403

Structural Properties of Eu-Doped GaN Investigated by Raman Spectroscopy  

SciTech Connect (OSTI)

Rare-earth (RE) impurities doped GaN are highly promising candidates for light emitting device applications due to their efficient electroluminescence properties at room temperature. Among those, Eu doped GaN has been identified as an excellent material for the red spectral region due to its strong emission at 620 nm. As a transition internal to the Eu doping atom (4f-4f), light emission originates in a much smaller complex than the more flexibly controllable quantum structures of wells, wires, and dots. This is thought to make the center less susceptible to structural defects and in particular radiation damage in the lattice host. Nevertheless, the lattice host is crucial for providing the excitation in from of free electrons and holes. In this respect, the actual lattice site Eu occupies in the host lattice, i.e. in GaN, is important. A large fraction of Eu atoms are typically inactive which must be attributed to their lattice site and local environment. GaN films implanted with Eu to concentrations of {approx}10{sup 18} cm{sup -3} were subjected to a highly directed beam of 500 keV He{sup +} at a dose of 5 x 10{sup 14} cm{sup -2}. By means of a shadow mask, irradiated and unexposed regions lie very close to each other on the same sample. We used optical and structural analysis to identify the exerted radiation damage. At the full radiation dose, photoluminescence intensity has decayed to {approx}0.01 of its initial value. From the dose dependence of the radiation decay we previously concluded, that this decay is in part due to the destruction of radiative Eu sites [J.W. Tringe, unpublished (2006)]. Along the transition from virgin to irradiated material we analyze the accumulated damage in terms of surface morphology (atomic force microscopy), crystallinity (x-ray diffraction), and phonon dispersion using micro-Raman spectroscopy. In addition to the well-studied E{sub 2}(high) mode, two new vibrational modes at 659 cm{sup -1} and 201 cm{sup -1} were observed in the Eu implanted and annealed sample, prior to He{sup +} irradiation. These modes are either remnants of the implantation damage or related to the Eu impurity. As such they can be indicative of the actual lattice site the Eu atom resides on. After irradiation, broad Raman modes at 300 cm-1 are being observed. This band indicates disorder activated Raman scattering (DARS) due to the radiation damage. An additional narrow mode appears at 672 cm{sup -1}, which can possibly be due to a nitrogen vacancy related vibrational mode. The continuous transition from irradiated to un-irradiated sample allows the direct evolution of radiation damage and its coordinated effects in structural, optical and vibrational properties. By its systematic correlation we anticipate to be able to elucidate the Eu lattice interaction and the processes of radiation damage.

Senawiratne, J; Xia, Y; Detchprohm, T; Tringe, J W; Stevens, C G; Wetzel, C

2006-06-20T23:59:59.000Z

404

Estimating the pressure of laser-induced plasma shockwave by stimulated Raman shift of lattice translational modes  

SciTech Connect (OSTI)

The current paper investigates stimulated Raman scattering (SRS) when laser-induced plasma is formed in heavy water by focusing an intense pulsed 532 nm Nd:YAG laser beam at room temperature. An unexpected low-frequency SRS line attributed to the lattice translational modes of ice-VII (D{sub 2}O) is observed. The pressure of the plasma shockwave is estimated using low-frequency SRS line shift.

Li Zhanlong [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); College of Physics, Jilin University, Changchun 130012 (China); Shan Xiaoning; Li Zuowei; Zhou Mi; Men Zhiwei [College of Physics, Jilin University, Changchun 130012 (China); Cao Junsheng [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Wang Yiding [College of Electronic Science and Engineering and Key Laboratory on Integrated Optoelectronics, Jilin University, Changchun 130012 (China); Sun Chenglin [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China)

2012-07-09T23:59:59.000Z

405

Study of the longitudinal distribution of power generated in a random distributed feedback Raman fibre laser with unidirectional pumping  

SciTech Connect (OSTI)

The longitudinal distribution of the Stokes-component power in a Raman fibre laser with a random distributed feedback and unidirectional pumping is measured. The fibre parameters (linear loss and Rayleigh backscattering coefficient) are calculated based on the distributions obtained. A numerical model is developed to describe the lasing power distribution. The simulation results are in good agreement with the experimental data. (optical fibres, lasers and amplifiers. properties and applications)

Churkin, D V; El-Taher, A E; Vatnik, I D; Babin, Sergei A

2012-09-30T23:59:59.000Z

406

Stimulated Raman scattering of beat wave of two counter-propagating X-mode lasers in a magnetized plasma  

SciTech Connect (OSTI)

Effects of transverse static magnetic field on stimulated Raman scattering (SRS) of the beat wave excited by two counter-propagating lasers are studied. Two counter-propagating lasers with frequency difference, ?{sub 1}??{sub 2}?2?{sub p}, drive a non resonant space charge beat mode at wave number k{sup ?}{sub 0}?k{sup ?}{sub 1}+k{sup ?}{sub 2} in a plasma, where k{sup ?}{sub 1} and k{sup ?}{sub 2} are wave vectors of lasers having frequencies ?{sub 1} and ?{sub 2}, respectively. The driven beat wave acts as a pump for SRS and excites parametrically a pair of plasma wave (?,k{sup ?}) and side band electromagnetic wave (?{sub 3},k{sup ?}{sub 3}) propagating in the sideward direction in such a way that momentum remains conserved. The growth rate of Raman process is maximum for side scattering at ?{sub s}=?/2 for lower values of applied magnetic field (?1?kG), which can be three fold by applying magnetic field ?5.0?kG. Thus, optimum value of magnetic field can be utilized to achieve maximum electron acceleration in counter propagating geometry of beat wave acceleration by reducing the growth rate of Raman process.

Verma, Kanika; Sajal, Vivek, E-mail: vsajal@rediffmail.com; Varshney, Prateek; Kumar, Ravindra; Sharma, Navneet K. [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307, UP (India)] [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307, UP (India)

2014-02-15T23:59:59.000Z

407

Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111) substrate  

SciTech Connect (OSTI)

The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE) on Si (111) substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E{sub 2} (high) and A{sub 1} (LO) phonon mode of InN core at 490 and 590 cm{sup -1} respectively and E{sub 2} (high) phonon mode of GaN shell at 573 cm{sup -1}. The free carrier concentration of InN core is found to be low in the order {approx} 10{sup 16} cm{sup -3} due to the screening of charge carriers by thin GaN shell. Diameter of InN core evaluated using the spatial correlation model is consistent with the transmission electron microscopic measurement of {approx}15 nm. The phonon-life time of core-shell nanowire structure is estimated to be {approx}0.4 ps. The micro-Raman mapping and its corresponding localised spectra for 325 nm excitation exhibit intense E{sub 2} (high) phonon mode of GaN shell at 573 cm{sup -1} as the decrease of laser interaction length and the signal intensity is quenched at the voids due to high spacing of NWs.

Sangeetha, P.; Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625 021 (India); Jeganathan, K. [Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli-620 024 (India)

2013-06-15T23:59:59.000Z

408

Multiferroic CuCrO{sub 2} under high pressure: In situ X-ray diffraction and Raman spectroscopic studies  

SciTech Connect (OSTI)

The compression behavior of delafossite compound CuCrO{sub 2} has been investigated by in situ x-ray diffraction (XRD) and Raman spectroscopic measurements up to 23.2 and 34?GPa, respectively. X-ray diffraction data show the stability of ambient rhombohedral structure up to ?23?GPa. Material shows large anisotropy in axial compression with c-axis compressibility, ?{sub c}?=?1.26?×?10{sup ?3}(1) GPa{sup ?1} and a-axis compressibility, ?{sub a}?=?8.90?×?10{sup ?3}(6) GPa{sup ?1}. Our XRD data show an irreversible broadening of diffraction peaks. Pressure volume data when fitted to 3rd order Birch-Murnaghan equation of state give the value of bulk modulus, B{sub 0}?=?156.7(2.8) GPa with its pressure derivative, B{sub 0}{sup ?} as 5.3(0.5). All the observed vibrational modes in Raman measurements show hardening with pressure. Appearance of a new mode at ?24?GPa indicates the structural phase transition in the compound. Our XRD and Raman results indicate that CuCrO{sub 2} may be transforming to an ordered rocksalt type structure under compression.

Garg, Alka B., E-mail: alkagarg@barc.gov.in; Mishra, A. K.; Pandey, K. K.; Sharma, Surinder M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2014-10-07T23:59:59.000Z

409

ARM - Measurement - Lidar polarization  

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

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410

Single-photon emission via Raman scattering from the levels with partially resolved hyperfine structure  

E-Print Network [OSTI]

The probability of emission of a single photon via Raman scattering of laser pulse on the three-level $\\Lambda$ - type atom in microcavity is studied. The duration of the pulse is considered to be short enough, so that the hyperfine structure of the upper level remains totally unresolved, while that of the lower level is totally resolved. The coherent laser pulse is assumed to be in resonance with the transition between one hyperfine structure component of the lower atomic level and all hyperfine structure components of the upper level, while the quantized cavity field is assumed to be in resonance with the transition between the other hyperfine structure component of the lower level and all components of the upper one. The dependence of the photon emission probability on the mutual orientation of polarization vectors of the cavity mode and of the coherent laser pulse is analyzed. Particularly, the case is investigated, when the total electronic angular momentum of the lower atomic level equals 1/2, which is true for the ground states of alkali atoms employed in the experiments on deterministic single photon emission. It is shown, that in this case the probability of photon emission equals zero for collinear polarizations of the photon and of the laser pulse, and the probability obtains its maximum value, when the angle between their polarizations equals 60 degrees.

V. A. Reshetov; I. V. Yevseyev

2009-11-24T23:59:59.000Z

411

Raman spectroscopic measurement of oxidation in supercritical water. 2: Conversion of isopropyl alcohol to acetone  

SciTech Connect (OSTI)

The oxidation of isopropyl alcohol in supercritical water has been investigated using Raman spectroscopy. Results for species concentration as a function of residence-time are presented for temperatures ranging from 400 to 480 C at constant pressure, 24.4 {+-} 0.3 MPa, and constant equivalence ratio, 0.88 {+-} 0.0. Acetone has been identified as the principal intermediate formed and subsequently destroyed, during the oxidation process. By assuming first-order kinetics for the destruction of both isopropyl alcohol and acetone, effective first-order rate constants have been determined from fits of the experimental data. Assuming Arrhenius behavior, the fits yield rate constants for isopropyl alcohol, k{sub eff,ipa} = 3.255 {times} 10{sup 22}(s{sup {minus}1}) exp [{minus}301.1 (kJ/mol)/RT], and for acetone, k{sub eff,ace} = 1.948 {times} 10{sup 10}(s{sup {minus}1}) exp[{minus}137.7(kJ/mol)/RT]. These results indicate that for temperatures greater than 425 C, the destruction of isopropyl alcohol proceeds faster than that of acetone.

Hunter, T.B.; Rice, S.F.; Hanush, R.G. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility] [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility

1996-11-01T23:59:59.000Z

412

Raman Spectroscopy Determination of Hole Concentration in p-Type GaSb  

SciTech Connect (OSTI)

Room temperature p-type GaSb bulk coupled mode spectra were measured as a function of hole concentration. These spectra were obtained using an optical system based on 752.55 nm excitation in order to obtain more sensitivity to bulk GaSb coupled mode scattering than possible with visible wavelength excitation-based systems. A relatively simple spectral model for the electronic contribution to the dielectric function was evaluated for determination of hole concentration from the bulk coupled mode spectra. Optically-derived values for hole concentration were determined by minimizing the sum of the residuals squared between an experimental and simulated spectrum as a function of total hole concentration and a plasmon damping parameter. Hole concentrations obtained from the Raman spectroscopic measurements deviated from the values determined from single field Hall effect measurements that were corrected to account for two band conduction by {approx}20% to {approx}65%. These deviations were attributed to the limitations of the spectral model employed and uncertainties in GaSb materials properties.

Maslar JE, Hurst WS, Wang CA

2007-04-05T23:59:59.000Z

413

Stokes--anti-Stokes Correlations in Raman Scattering from Diamond Membranes  

E-Print Network [OSTI]

We investigate the arrival statistics of Stokes (S) and anti-Stokes (aS) Raman photons generated in diamond membranes. Strong quantum correlations between the S and aS signals are observed, which implies that the two processes share the same phonon, that is, the phonon excited by the S process is consumed in the aS process. We show that the intensity cross-correlation $g_{\\rm S,aS}^{(2)}(0)$, which describes the simultaneous detection of Stokes and anti-Stokes photons, decreases steadily with laser power as $1/{\\rm P_L}$. Contrary to many other material systems, diamond exhibits a maximum $g_{\\rm S,aS}^{(2)}(0)$ at very low pump powers, implying that the Stokes-induced aS photons outnumber the thermally generated aS photons. On the other hand, the coincidence rate shows a quadratic plus cubic power dependence, which indicates a departure from the Stokes-induced anti-Stokes process.

Kasperczyk, Mark; Neu, Elke; Maletinsky, Patrick; Novotny, Lukas

2015-01-01T23:59:59.000Z

414

Structure disorder degree of polysilicon thin films grown by different processing: Constant C from Raman spectroscopy  

SciTech Connect (OSTI)

Flat, low-stress, boron-doped polysilicon thin films were prepared on single crystalline silicon substrates by low pressure chemical vapor deposition. It was found that the polysilicon films with different deposition processing have different microstructure properties. The confinement effect, tensile stresses, defects, and the Fano effect all have a great influence on the line shape of Raman scattering peak. But the effect results are different. The microstructure and the surface layer are two important mechanisms dominating the internal stress in three types of polysilicon thin films. For low-stress polysilicon thin film, the tensile stresses are mainly due to the change of microstructure after thermal annealing. But the tensile stresses in flat polysilicon thin film are induced by the silicon carbide layer at surface. After the thin film doped with boron atoms, the phenomenon of the tensile stresses increasing can be explained by the change of microstructure and the increase in the content of silicon carbide. We also investigated the disorder degree states for three polysilicon thin films by analyzing a constant C. It was found that the disorder degree of low-stress polysilicon thin film larger than that of flat and boron-doped polysilicon thin films due to the phase transformation after annealing. After the flat polysilicon thin film doped with boron atoms, there is no obvious change in the disorder degree and the disorder degree in some regions even decreases.

Wang, Quan, E-mail: wangq@mail.ujs.edu.cn [School of mechanical engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Yanmin; Hu, Ran; Ren, Naifei [School of mechanical engineering, Jiangsu University, Zhenjiang 212013 (China); Ge, Daohan [School of mechanical engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2013-11-14T23:59:59.000Z

415

Raman Scattering Sensor for Control of the Acid Alkylation Process in Gasoline Production  

SciTech Connect (OSTI)

Gasoline refineries utilize a process called acid alkylation to increase the octane rating of blended gasoline, and this is the single most expensive process in the refinery. For process efficiency and safety reasons, the sulfuric acid can only be used while it is in the concentration range of 98 to 86 %. The conventional technique to monitor the acid concentration is time consuming and is typically conducted only a few times per day. This results in running higher acid concentrations than they would like to ensure that the process proceeds uninterrupted. Maintaining an excessively high acid concentration costs the refineries millions of dollars each year. Using SBIR funding, Process Instruments Inc. has developed an inline sensor for real time monitoring of acid concentrations in gasoline refinery alkylation units. Real time data was then collected over time from the instrument and its responses were matched up with the laboratory analysis. A model was then developed to correlate the laboratory acid values to the Raman signal that is transmitted back to the instrument from the process stream. The instrument was then used to demonstrate that it could create real-time predictions of the acid concentrations. The results from this test showed that the instrument could accurately predict the acid concentrations to within ~0.15% acid strength, and this level of prediction proved to be similar or better then the laboratory analysis. By utilizing a sensor for process monitoring the most economic acid concentrations can be maintained. A single smaller refinery (50,000 barrels/day) estimates that they should save over $120,000/year, with larger refineries saving considerably more.

Uibel, Rory, H.; Smith, Lee M.; Benner, Robert, E.

2006-04-19T23:59:59.000Z

416

QUANTIFYING FOREST ABOVEGROUND CARBON POOLS AND FLUXES USING MULTI-TEMPORAL LIDAR A report on field monitoring, remote sensing MMV, GIS integration, and modeling results for forestry field validation test to quantify aboveground tree biomass and carbon  

SciTech Connect (OSTI)

Sound policy recommendations relating to the role of forest management in mitigating atmospheric carbon dioxide (CO{sub 2}) depend upon establishing accurate methodologies for quantifying forest carbon pools for large tracts of land that can be dynamically updated over time. Light Detection and Ranging (LiDAR) remote sensing is a promising technology for achieving accurate estimates of aboveground biomass and thereby carbon pools; however, not much is known about the accuracy of estimating biomass change and carbon flux from repeat LiDAR acquisitions containing different data sampling characteristics. In this study, discrete return airborne LiDAR data was collected in 2003 and 2009 across {approx}20,000 hectares (ha) of an actively managed, mixed conifer forest landscape in northern Idaho, USA. Forest inventory plots, established via a random stratified sampling design, were established and sampled in 2003 and 2009. The Random Forest machine learning algorithm was used to establish statistical relationships between inventory data and forest structural metrics derived from the LiDAR acquisitions. Aboveground biomass maps were created for the study area based on statistical relationships developed at the plot level. Over this 6-year period, we found that the mean increase in biomass due to forest growth across the non-harvested portions of the study area was 4.8 metric ton/hectare (Mg/ha). In these non-harvested areas, we found a significant difference in biomass increase among forest successional stages, with a higher biomass increase in mature and old forest compared to stand initiation and young forest. Approximately 20% of the landscape had been disturbed by harvest activities during the six-year time period, representing a biomass loss of >70 Mg/ha in these areas. During the study period, these harvest activities outweighed growth at the landscape scale, resulting in an overall loss in aboveground carbon at this site. The 30-fold increase in sampling density between the 2003 and 2009 did not affect the biomass estimates. Overall, LiDAR data coupled with field reference data offer a powerful method for calculating pools and changes in aboveground carbon in forested systems. The results of our study suggest that multitemporal LiDAR-based approaches are likely to be useful for high quality estimates of aboveground carbon change in conifer forest systems.

Lee Spangler; Lee A. Vierling; Eva K. Stand; Andrew T. Hudak; Jan U.H. Eitel; Sebastian Martinuzzi

2012-04-01T23:59:59.000Z

417

Determination of saccharides and ethanol from biomass conversion using Raman spectroscopy: Effects of pretreatment and enzyme composition  

SciTech Connect (OSTI)

This dissertation focuses on the development of facile and rapid quantitative Raman spectroscopy measurements for the determination of conversion products in producing bioethanol from corn stover. Raman spectroscopy was chosen to determine glucose, xylose and ethanol in complex hydrolysis and fermentation matrices. Chapter 1 describes the motives and main goals of this work, and includes an introduction to biomass, commonly used pretreatment methods, hydrolysis and fermentation reactions. The principles of Raman spectroscopy, its advantages and applications related to biomass analysis are also illustrated. Chapter 2 and 3 comprise two published or submitted manuscripts, and the thesis concludes with an appendix. In Chapter 2, a Raman spectroscopic protocol is described to study the efficiency of enzymatic hydrolysis of cellulose by measuring the main product in hydrolysate, glucose. Two commonly utilized pretreatment methods were investigated in order to understand their effect on glucose measurements by Raman spectroscopy. Second, a similar method was set up to determine the concentration of ethanol in fermentation broth. Both of these measurements are challenged by the presence of complex matrices. In Chapter 3, a quantitative comparison of pretreatment protocols and the effect of enzyme composition are studied using systematic methods. A multipeak fitting algorithm was developed to analyze spectra of hydrolysate containing two analytes: glucose and xylose. Chapter 4 concludes with a future perspective of this research area. An appendix describes a convenient, rapid spectrophotometric method developed to measure cadmium in water. This method requires relatively low cost instrumentation and can be used in microgravity, such as space shuttles or the International Space Station. This work was performed under the supervision of Professor Marc Porter while at Iowa State University. Research related to producing biofuel from bio-renewable resources, especially bioethanol from biomass, has grown significantly in the past decade due to the high demand and rising costs of fossil fuels. More than 3 percent of the energy consumption in the U.S. is derived from renewable biomass, mostly through industrial heat and steam production by the pulp and paper industry, and electricity generation from municipal solid waste (MSW) and forest industry residues. The utilization of food-based biomass to make fuels has been widely criticized because it may increase food shortages throughout the world and raise the cost of food. Thus, nonfood-based and plentiful lignocellulosic feedstocks, such as corn stover, perennial grass, bagasse, sorghum, wheat/rice straw, herbaceous and woody crops, have great potential to be new bio-renewable sources for energy production. Given that many varieties of biomass are available, there is need for a rapid, simple, high-throughput method to screen the conversion of many plant varieties. The most suitable species for each geographic region must be determined, as well as the optimal stage of harvest, impacts of environmental conditions (temperature, soil, pH, etc.). Various genetically modified plants should be studied in order to establish the desired biomass in bioethanol production. The main screening challenge, however, is the complexity of plant cell wall structures that make reliable and sensitive analysis difficult. To date, one of the most popular methods to produce lignocellulosic ethanol is to perform enzymatic hydrolysis followed by fermentation of the hydrolysate with yeast. There are several vital needs related to the field of chemistry that have been suggested as primary research foci needed to effectively improve lignocellulosic ethanol production. These topics include overcoming the recalcitrance of cellulosic biomass, the pervasiveness of pretreatment, advanced biological processing and better feedstocks. In this thesis, a novel approach using Raman spectroscopy has been developed to address important issues related to bioethanol generation, which will aid the research aimed to solve the topics m

Shih, Chien-Ju

2010-05-16T23:59:59.000Z

418

Enhancement of surface phonon modes in the Raman spectrum of ZnSe nanoparticles on adsorption of 4-mercaptopyridine  

SciTech Connect (OSTI)

By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm{sup ?1}) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations.

Islam, Syed K.; Lombardi, John R. [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)] [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)

2014-02-21T23:59:59.000Z

419

Monitoring Long-Range Electron Transfer Pathways in Proteins by Stimulated Attosecond Broadband X-ray Raman Spectroscopy  

SciTech Connect (OSTI)

Long-range electron transfer (ET) plays a key role in many biological energy conversion and synthesis processes. We show that nonlinear spectroscopy with attosecond X-ray pulses provides a real time movie of the evolving oxidation states and electron densities around atoms, and can probe these processes with high spatial and temporal resolution. This is demonstrated in a simulation study of the stimulated X-ray Raman (SXRS) signals in Re-modified azurin, which had long served as a benchmark for long-range ET in proteins. Nonlinear SXRS signals are sensitive to the local electronic structure and should offer a novel window for long-range ET.

Zhang, Yu; Biggs, Jason; Govind, Niranjan; Mukamel, Shaul

2014-10-09T23:59:59.000Z

420

VOLUME 84, NUMBER 3 P H Y S I C A L R E V I E W L E T T E R S 17 JANUARY 2000 Beyond Optical Molasses: 3D Raman Sideband Cooling of Atomic Cesium  

E-Print Network [OSTI]

. The technique is based on 3D degenerate Raman sideband cooling in optical lattices and remains efficient even [1]. Although other techniques, such as evaporative cooling [2], velocity-selective coherent Molasses: 3D Raman Sideband Cooling of Atomic Cesium to High Phase-Space Density Andrew J. Kerman, Vladan

Vuletic, Vladan

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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.


421

Raman spectroscopy of solutions and interfaces containing nitrogen dioxide, water, and 1,4 dioxane: Evidence for repulsion of surface water by NO{sub 2} gas  

SciTech Connect (OSTI)

The interaction of water, 1,4 dioxane, and gaseous nitrogen dioxide, has been studied as a function of distance measured through the liquid-vapour interface by Raman spectroscopy with a narrow (<0.1 mm) laser beam directed parallel to the interface. The Raman spectra show that water is present at the surface of a dioxane-water mixture when gaseous NO{sub 2} is absent, but is virtually absent from the surface of a dioxane-water mixture when gaseous NO{sub 2} is present. This is consistent with recent theoretical calculations that show NO{sub 2} to be mildly hydrophobic.

Murdachaew, Garold [Institute of Chemistry and the Fritz Haber Research Center for Molecular Dynamics, Hebrew University, Jerusalem 91904 (Israel)] [Institute of Chemistry and the Fritz Haber Research Center for Molecular Dynamics, Hebrew University, Jerusalem 91904 (Israel); Varner, Mychel E.; Veer, Wytze E. van der [Department of Chemistry, University of California, Irvine, California 92697 (United States)] [Department of Chemistry, University of California, Irvine, California 92697 (United States); Gerber, R. Benny [Institute of Chemistry and the Fritz Haber Research Center for Molecular Dynamics, Hebrew University, Jerusalem 91904 (Israel) [Institute of Chemistry and the Fritz Haber Research Center for Molecular Dynamics, Hebrew University, Jerusalem 91904 (Israel); Department of Chemistry, University of California, Irvine, California 92697 (United States); Phillips, Leon F., E-mail: leon.phillips@canterbury.ac.nz [Department of Chemistry, University of California, Irvine, California 92697 (United States); Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand)

2014-05-14T23:59:59.000Z

422

Thin and thick cloud top height retrieval algorithm with the Infrared Camera and LIDAR of the JEM-EUSO Space Mission  

E-Print Network [OSTI]

The origin of cosmic rays have remained a mistery for more than a century. JEM-EUSO is a pioneer space-based telescope that will be located at the International Space Station (ISS) and its aim is to detect Ultra High Energy Cosmic Rays (UHECR) and Extremely High Energy Cosmic Rays (EHECR) by observing the atmosphere. Unlike ground-based telescopes, JEM-EUSO will observe from upwards, and therefore, for a properly UHECR reconstruction under cloudy conditions, a key element of JEM-EUSO is an Atmospheric Monitoring System (AMS). This AMS consists of a space qualified bi-spectral Infrared Camera, that will provide the cloud coverage and cloud top height in the JEM-EUSO Field of View (FoV) and a LIDAR, that will measure the atmospheric optical depth in the direction it has been shot. In this paper we will explain the effects of clouds for the determination of the UHECR arrival direction. Moreover, since the cloud top height retrieval is crucial to analyze the UHECR and EHECR events under cloudy conditions, the ret...

Sáez-Cano, G; del Peral, L; Neronov, A; Wada, S; Frías, M D Rodríguez

2015-01-01T23:59:59.000Z

423

Temperature dependent Raman scattering studies of three dimensional topological insulators Bi{sub 2}Se{sub 3}  

SciTech Connect (OSTI)

We investigate the temperature dependent (83?K?T?523?K) frequency shift of 2A{sub g}{sup 1} and 1E{sub g}{sup 2} phonon modes in the three dimensional topological insulator Bi{sub 2}Se{sub 3}, using Raman spectroscopy. The high quality single crystals of Bi{sub 2}Se{sub 3} were grown using a modified Bridgman technique and characterized by Laue diffraction and high resolution transmission electron microscopy. A significant broadening in the line shape and red-shift in the frequencies were observed with increase in temperature. Polarized Raman scattering measurement shows a strong polarization effect of A{sub g}{sup 1} and A{sub g}{sup 2} phonon modes which confirms the good quality single crystals of Bi{sub 2}Se{sub 3}. Temperature co-efficient for A{sub 1g}{sup 1},?E{sub g}{sup 2}, and A{sub 1g}{sup 2} modes was estimated to be ?1.44?×?10{sup ?2}, ?1.94?×?10{sup ?2}, and ?1.95?×?10{sup ?2}?cm{sup ?1}?K, respectively. Our results shed light on anharmonic properties of Bi{sub 2}Se{sub 3}.

Irfan, Bushra; Chatterjee, Ratnamala, E-mail: rmala@physics.iitd.ac.in [Department of Physics, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India); Sahoo, Satyaprakash; Gaur, Anand P. S.; Ahmadi, Majid; Katiyar, Ram S. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931 (United States); Guinel, Maxime J.-F. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00931 (United States); Department of Chemistry, College of Natural Sciences, University of Puerto Rico, P.O. Box 70377, San Juan, Puerto Rico 00936-8377 (United States)

2014-05-07T23:59:59.000Z

424

Laser irradiation effects on the CdTe/ZnTe quantum dot structure studied by Raman and AFM spectroscopy  

SciTech Connect (OSTI)

Micro-Raman spectroscopy has been applied to investigate the impact of laser irradiation on semiconducting CdTe/ZnTe quantum dots (QDs) structures. A reference sample (without dots) was also studied for comparison. Both samples were grown by molecular beam epitaxy technique on the p-type GaAs substrate. The Raman spectra have been recorded for different time of a laser exposure and for various laser powers. The spectra for both samples exhibit peak related to the localized longitudinal (LO) ZnTe phonon of a wavenumber equal to 210 cm{sup -1}. For the QD sample, a broad band corresponding to the LO CdTe phonon related to the QD-layer appears at a wavenumber of 160 cm{sup -1}. With increasing time of a laser beam exposure and laser power, the spectra get dominated by tellurium-related peaks appearing at wavenumbers around 120 cm{sup -1} and 140 cm{sup -1}. Simultaneously, the ZnTe surface undergoes rising damage, with the formation of Te aggregates at the pinhole edge as reveal atomic force microscopy observations. Local temperature of irradiated region has been estimated from the anti-Stokes/Stokes ratio of the Te modes intensity and it was found to be close or exceeding ZnTe melting point. Thus, the laser damage can be explained by the ablation process.

Zielony, E.; Placzek-Popko, E.; Henrykowski, A.; Gumienny, Z.; Kamyczek, P.; Jacak, J. [Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Nowakowski, P.; Karczewski, G. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland)

2012-09-15T23:59:59.000Z

425

Evolution of magnetic and superconducting fluctuations with doping of high-T{sub c} superconductors : an electronic Raman scattering study.  

SciTech Connect (OSTI)

For YBa{sub 2}Cu{sub 3}O{sub 6+{delta}} and Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 3{+-}{delta}} superconductors, electronic Raman scattering from high- and low-energy excitations has been studied in relation to the hole doping level, temperature, and energy of the incident photons. For underdoped superconductors, it is concluded that short range antiferromagnetic (AF) correlations persist with hole doping and doped single holes are incoherent in the AF environment. Above the superconducting (SC) transition temperature T{sub c} the system exhibits a sharp Raman resonance of B{sub 1g} symmetry and about 75 meV energy and a pseudogap for electron-hole excitations below 75 meV, a manifestation of a partially coherent state forming from doped incoherent quasi-particles. The occupancy of the coherent state increases with cooling until phase ordering at T{sub c} produces a global SC state.

Blumberg, G.

1998-01-14T23:59:59.000Z

426

Nonlinear Raman Shift Induced by Exciton-to-Trion Transformation in Suspended Trilayer MoS2  

E-Print Network [OSTI]

Layered two-dimensional (2D) semiconductors such as molybdenum disulfide (MoS2) have recently attracted remarkable attention because of their unique physical properties. Here, we use photoluminescence (PL) and Raman spectroscopy to study the formation of the so- called trions in a synthesized freestanding trilayer MoS2. A trion is a charged quasi-particle formed by adding one electron or hole to a neutral exciton (a bound electron-hole pair). We demonstrate accurate control over the transformation of excitons to trions by tuning the power of the optical pump (laser). Increasing the power of the excitation laser beyond a certain threshold (~ 4 mW) allows modulation of trion-to-exciton PL intensity ratio as well as the spectral linewidth of both trions and excitons. Via a systematic and complementary Raman analysis we disclose a strong coupling between laser induced exciton-to-trion transformation and the characteristic phononic vibrations of MoS2. The onset of such an optical transformation corresponds to the ...

Taghinejad, Hossein; Tarasov, Alexey; Tsai, Meng-Yen; Hosseinnia, Amir H; Campbell, Philip M; Eftekhar, Ali A; Vogel, Eric M; Adibi, Ali

2015-01-01T23:59:59.000Z

427

Synthesis of silver particles on copper substrates using ethanol-based solution for surface-enhanced Raman spectroscopy  

SciTech Connect (OSTI)

The displacement reaction of AgNO{sub 3} and copper metal is an effective and economical way to fabricate Ag-Cu surface enhanced Raman scattering (SERS) substrates. Aqueous solutions of AgNO{sub 3} are usually used for substrate preparation. In this work, a new method for Ag-Cu SERS substrate preparation is proposed, which uses an ethanol solution rather than an aqueous AgNO{sub 3} solution. Analysis of the surface morphologies of sample substrates by field emission scanning electron microscopy (FESEM) showed that the silver nanoparticles prepared by this new method were more regular than those prepared in the traditional aqueous solution. The SERS spectra of Rhodamine 6G (R6G) adsorbed on these Ag-Cu substrates were then investigated and compared. It was found that the Ag-Cu substrates prepared by this method provide significant improvements in Raman signal sensitivity and large-area uniformity. The enhancement factor of this new substrate is about 330 times higher than that prepared using an aqueous AgNO{sub 3} solution under identical experimental conditions. It was also found that 70% of the original sensitivity of the substrate remains after 15 days of exposure to air.

Chen, Li, E-mail: CL2009@cqu.edu.cn; Zhang, Zuojun; Chen, Gang; Zhou, Hui [Defense Key Disciplines Lab of Novel Micro-nano Devices and System Technology, and Key Laboratory of Optoelectronic Technology and Systems, Chongqing University, Chongqing 400044 (China)] [Defense Key Disciplines Lab of Novel Micro-nano Devices and System Technology, and Key Laboratory of Optoelectronic Technology and Systems, Chongqing University, Chongqing 400044 (China); Lai, Chunhong [Defense Key Disciplines Lab of Novel Micro-nano Devices and System Technology, and Key Laboratory of Optoelectronic Technology and Systems, Chongqing University, Chongqing 400044 (China) [Defense Key Disciplines Lab of Novel Micro-nano Devices and System Technology, and Key Laboratory of Optoelectronic Technology and Systems, Chongqing University, Chongqing 400044 (China); School of Physics and Electronic Information, China West Normal University, NanChong 637002 (China)

2014-03-15T23:59:59.000Z

428

Monitoring of tritium purity during long-term circulation in the KATRIN test experiment LOOPINO using laser Raman spectroscopy  

E-Print Network [OSTI]

The gas circulation loop LOOPINO has been set up and commissioned at Tritium Laboratory Karlsruhe (TLK) to perform Raman measurements of circulating tritium mixtures under conditions similar to the inner loop system of the neutrino-mass experiment KATRIN, which is currently under construction. A custom-made interface is used to connect the tritium containing measurement cell, located inside a glove box, with the Raman setup standing on the outside. A tritium sample (purity > 95%, 20 kPa total pressure) was circulated in LOOPINO for more than three weeks with a total throughput of 770 g of tritium. Compositional changes in the sample and the formation of tritiated and deuterated methanes CT_(4-n)X_n (X=H,D; n=0,1) were observed. Both effects are caused by hydrogen isotope exchange reactions and gas-wall interactions, due to tritium {\\beta} decay. A precision of 0.1% was achieved for the monitoring of the T_2 Q_1-branch, which fulfills the requirements for the KATRIN experiment and demonstrates the feasibility ...

Fischer, Sebastian; Schlösser, Magnus; Bornschein, Beate; Drexlin, Guido; Priester, Florian; Lewis, Richard J; Telle, Helmut H

2012-01-01T23:59:59.000Z

429

Resonance Raman and theoretical investigation of the photodissociation dynamics of benzamide in S{sub 3} state  

SciTech Connect (OSTI)

Resonance Raman spectra were obtained for benzamide in methanol and acetonitrile solutions with excitation wavelengths in resonance with the S{sub 3} state. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with the motions mainly along the benzene ring C=C stretch {nu}{sub 9}, the Ph-CO-NH{sub 2} and ring benzene stretch {nu}{sub 14}, the CCH in plane bend {nu}{sub 17}, the Ph-CO-NH{sub 2} stretch and NH{sub 2} rock {nu}{sub 19}, the ring trigonal bend {nu}{sub 23}, and the ring deformation and Ph-CO-NH{sub 2} stretch {nu}{sub 29}. A preliminary resonance Raman intensity analysis was done, and the results were compared to those previously reported for acetophenone to examine the substituent effect. Solvent effect on the short-time photodissociation dynamics of benzamide was also examined. A conical intersection point S{sub 2}/S{sub 3} between S{sub 3} and S{sub 2} potential energy surfaces of benzamide was determined by using a complete active space self-consistent field theory computations. The structural differences and similarities between S{sub 3}/S{sub 2} point and S{sub 0} were examined, and the results were used to correlate to the Franck-Condon photodissociation dynamics of benzamide in S{sub 3} state.

Pei Kemei; Ma Yufang; Zheng Xuming [Department of Chemistry and State Key Laboratory of ATMMT (MOE), Zhejiang Sci-Tech University, Hangzhou 310018 (China)

2008-06-14T23:59:59.000Z

430

UV-Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption studies of model and bulk heterogeneous catalysts  

SciTech Connect (OSTI)

X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (TPD) have been used to investigate the surface structure of model heterogeneous catalysts in ultra-high vacuum (UHV). UV-Raman spectroscopy has been used to probe the structure of bulk model catalysts in ambient and reaction conditions. The structural information obtained through UV-Raman spectroscopy has been correlated with both the UHV surface analysis and reaction results. The present day propylene and ethylene polymerization catalysts (Ziegler-Natta catalysts) are prepared by deposition of TiCl{sub 4} and a Al(Et){sub 3} co-catalyst on a microporous Mg-ethoxide support that is prepared from MgCl{sub 2} and ethanol. A model thin film catalyst is prepared by depositing metallic Mg on a Au foil in a UHV chamber in a background of TiCl{sub 4} in the gas phase. XPS results indicate that the Mg is completely oxidized to MgCl{sub 2} by TiCl{sub 4} resulting in a thin film of MgCl{sub 2}/TiCl{sub x}, where x = 2, 3, and 4. To prepare an active catalyst, the thin film of MgCl{sub 2}/TiCl{sub x} on Au foil is enclosed in a high pressure cell contained within the UHV chamber and exposed to {approx}1 Torr of Al(Et){sub 3}.

Tewell, Craig R.

2002-08-19T23:59:59.000Z

431

Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten masks: A method to map the free-carrier  

E-Print Network [OSTI]

Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten properties of two epitaxial-laterally overgrown GaN structures with tungsten masks in 1100 and 1120 direction by tungsten masks3 to prevent the in-diffusion of silicon and oxygen atoms in the overgrown GaN, which

Nabben, Reinhard

432

Second-order Raman spectra of single and multiwalled carbon nanotubes Institut fur Festkorperphysik, Technische Universtat Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany  

E-Print Network [OSTI]

. The excitation-energy dependence of the D and DÃ? modes in single-walled nanotubes is 38 and 90 cm 1 /eSecond-order Raman spectra of single and multiwalled carbon nanotubes C. Thomsen Institut fu of single- walled nanotubes softens by 30 cm 1 over the value of graphite. A comparison of the phonon

Nabben, Reinhard

433

Thermal and structural stability of single- and multi-walled carbon nanotubes up to 1800 °C in Argon studied by Raman spectroscopy and transmission electron microscopy  

SciTech Connect (OSTI)

Graphical abstract: Display Omitted Highlights: ? Structural stability of carbon nanotubes up to 1800 °C in Argon (?0.05 MPa). ? Thorough TEM and Raman spectroscopy of as received and heat treated CNTs. ? Analyses on the extent of structural changes during high temperature exposure. ? Discussion on safe upper temperature limit for practical use of SWCNTs and MWCNTs. -- Abstract: Effect of high temperature exposure (up to 1800 °C) on morphology of single- and multi-walled carbon nanotubes in Argon atmosphere has been studied using Raman spectroscopy and transmission electron microscopy. Although, as received nanotubes contained irregular graphene layers and other structural defects, microscopic observations revealed that heat treatment in Argon reduced the defect density and helped proper alignment of graphene layers. Raman spectra of as received and heat treated nanotubes strongly reinforced the microscopic observations. While, D-band to G-band intensity ratio in Raman spectra of 1800 °C heat treated multiwalled nanotubes reduced by ?43% over as received one, this ratio for heat treated singlewalled nanotubes was ?27% lower than that of the untreated specimen. Present study suggested that although, multiwalled nanotubes were structurally stable up to 1800 °C in an inert atmosphere having only a few nano-scale defects, singlewalled nanotubes suffered considerable damage at 1800 °C due to much thinner dimension than the former.

Sarkar, Soumya [Non-oxide Ceramics and Composites Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CG and CRI), 196 Raja S.C. Mullick Road, Kolkata 700 032 (India)] [Non-oxide Ceramics and Composites Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CG and CRI), 196 Raja S.C. Mullick Road, Kolkata 700 032 (India); Das, Probal Kr., E-mail: probal@cgcri.res.in [Non-oxide Ceramics and Composites Division, CSIR-Central Glass and Ceramic Research Institute (CSIR-CG and CRI), 196 Raja S.C. Mullick Road, Kolkata 700 032 (India)

2013-01-15T23:59:59.000Z

434

Micro-Raman spectroscopy of mechanically exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2Te3 materials  

E-Print Network [OSTI]

Micro-Raman spectroscopy of mechanically exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2-like" exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2Te3. It is found that crystal symmetry breaking

435

Raman spectrum and ESR of Pr0.5Ca0.4Sr0.1MnO3  

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

Raman spectrum and ESR of Pr 0.5 Ca 0.4 Sr 0.1 MnO 3 H.-D. Zhou a , G. Li a , F. Liu a , S.-J. Feng a , Y. Liu a , X.-G. Li a, * , J. Fang b a Structure Research Laboratory,...

436

Coherent superposition of M-states in a single rovibrational level of H2 by Stark-induced adiabatic Raman passage  

E-Print Network [OSTI]

2014) We prepare an ensemble of isolated rovibrationally excited (v = 1, J = 2) H2 molecules in a phase possibilities for investigations of phase-locked reaction dynamics. Although considerable effort has been spent- locked superposition of magnetic sublevels M using Stark-induced adiabatic Raman passage with linearly

Zare, Richard N.

437

Resonant-Raman intensities and transition energies of the E11 transition in carbon nanotubes * J. Maultzsch,1 S. Reich,2 and C. Thomsen1  

E-Print Network [OSTI]

Resonant-Raman intensities and transition energies of the E11 transition in carbon nanotubes H- troscopy. Radial breathing mode spectra were collected varying the excitation energy in the near-infrared from 1.15 to 1.48 eV. From resonance profiles we obtained the E11 S energies of 11 nanotubes, extending

Nabben, Reinhard

438

Soret Effect Study on High-Pressure CO2-Water Solutions Using UV-Raman Spectroscopy and a Concentric-Tube Optical Cell  

SciTech Connect (OSTI)

Spatially resolved deep-UV Raman spectroscopy was applied to solutions of CO2 and H2O (or D2O), which were subject to a temperature gradient in a thermally regulated high-pressure concentric-tube Raman cell in an attempt to measure a Soret effect in the vicinity of the critical point of CO2. Although Raman spectra of solutions of CO2 dissolved in D2O at 10 MPa and temperatures near the critical point of CO2 had adequate signal-to-noise and spatial resolution to observe a Soret effect with a Soret coefficient with magnitude of |ST| > 0.03, no evidence for an effect of this size was obtained for applied temperature gradients up to 19oC. The presence of 1 M NaCl did not make a difference. In contrast, the concentration of CO2 dissolved in H2O was shown to vary significantly across the temperature gradient when excess CO2 was present, but the results could be explained simply by the variation in CO2 solubility over the temperature range and not to kinetic factors. For mixtures of D2O dissolved in scCO2 at 10 MPa and temperatures close to the critical point of CO2, the Raman peaks for H2O were too weak to measure with confidence even at the limit of D2O solubility.

Windisch, Charles F.; McGrail, B. Peter; Maupin, Gary D.

2012-01-01T23:59:59.000Z

439

Stimulated Raman adiabatic passage from an atomic to a molecular Bose-Einstein condensate P. D. Drummond and K. V. Kheruntsyan  

E-Print Network [OSTI]

to maintain high conversion efficiencies with smaller Rabi frequencies and under experimentally less demanding of the condensates. The result is that the STIRAP process appears feasible at high laser pulse intensities, providedStimulated Raman adiabatic passage from an atomic to a molecular Bose-Einstein condensate P. D

Heinzen, Daniel J.

440

Rabi Wave Packets and Peculiarities of Raman Scattering in Carbon Nanotubes, Produced by High Energy Ion Beam Modification of Diamond Single Crystals  

E-Print Network [OSTI]

QED-model for multichain coupled qubit system, proposed in \\cite{Part1}, was confirmed by Raman scattering studies of quasi-1D carbon zigzag-shaped nanotubes (CZSNTs), produced by high energy ion beam modification of natural diamond single crystals. Multichain coupled qubit system represents itself Su-Schriffer-Heeger $\\sigma$-polaron lattice, formed in CZSNTs plus quantized external electromagnetic (EM) field. New quantum optics phenomenon - Rabi waves, predicted in \\cite{Slepyan_Yerchak} has experimentally been identified for the first time. It is shown, that Raman spectra in quasi-1D CZSNTs are quite different in comparison with well known Raman spectra in 2D those ones. They characterized by semiclassical consideration by the only one vibronic mode of Su-Schriffer-Heeger $\\sigma$-polaron lattice instead of longitudinal and transverse optical phonon $G^+$ and $G^-$modes and the out-of-plane radial breathing mode, which are observed in Raman spectra of 2D single wall nanotubes. It is consequence of 2D - 1D transition in all physical properties of nanotubes. It is shown, that strong electron-photon coupling takes place in CZSNTs by interaction with EM-field and quantum nature of EM-field has to be taken into account. It has been done for the first time in stationary spectroscopy at all. All optical spectra, in particular, Raman spectra are registered by usual stationary measurement technique in nonequilibrium conditions, which are the consequence of Rabi wave packets' formation. It leads in its turn to appearance of additional lines, corresponding to revival part of inversion dependence of joint EM-field + matter system in frequency representation.

Dmitry Yearchuck; Alla Dovlatova

2011-05-26T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" 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.


441

Using Radar, Lidar and Radiometer Data from NSA and SHEBA to Quantify Cloud Property Effects on the Surface Heat Budget in the Arctic  

SciTech Connect (OSTI)

Cloud and radiation data from two distinctly different Arctic areas are analyzed to study the differences between coastal Alaskan and open Arctic Ocean region clouds and their respective influence on the surface radiation budget. The cloud and radiation datasets were obtained from (1) the DOE North Slope of Alaska (NSA) facility in the coastal town of Barrow, Alaska, and (2) the SHEBA field program, which was conducted from an icebreaker frozen in, and drifting with, the sea-ice for one year in the Western Arctic Ocean. Radar, lidar, radiometer, and sounding measurements from both locations were used to produce annual cycles of cloud occurrence and height, atmospheric temperature and humidity, surface longwave and shortwave broadband fluxes, surface albedo, and cloud radiative forcing. In general, both regions revealed a similar annual trend of cloud occurrence fraction with minimum values in winter (60-75%) and maximum values during spring, summer and fall (80-90%). However, the annual average cloud occurrence fraction for SHEBA (76%) was lower than the 6-year average cloud occurrence at NSA (92%). Both Arctic areas also showed similar annual cycle trends of cloud forcing with clouds warming the surface through most of the year and a period of surface cooling during the summer, when cloud shading effects overwhelm cloud greenhouse effects. The greatest difference between the two regions was observed in the magnitude of the cloud cooling effect (i.e., shortwave cloud forcing), which was significantly stronger at NSA and lasted for a longer period of time than at SHEBA. This is predominantly due to the longer and stronger melt season at NSA (i.e., albedo values that are much lower coupled with Sun angles that are somewhat higher) than the melt season observed over the ice pack at SHEBA. Longwave cloud forcing values were comparable between the two sites indicating a general similarity in cloudiness and atmospheric temperature and humidity structure between the two regions.

Janet Intrieri; Mathhew Shupe

2005-01-01T23:59:59.000Z

442

Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy  

SciTech Connect (OSTI)

The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

Shur, V. Ya., E-mail: vladimir.shur@urfu.ru; Zelenovskiy, P. S. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

2014-08-14T23:59:59.000Z

443

Two-beam ultrabroadband coherent anti-Stokes Raman spectroscopy for high resolution gas-phase multiplex imaging  

SciTech Connect (OSTI)

We propose and develop a method for wideband coherent anti-Stokes Raman spectroscopy (CARS) in the gas phase and demonstrate the single-shot measurement of N{sub 2}, H{sub 2}, CO{sub 2}, O{sub 2}, and CH{sub 4}. Pure-rotational and vibrational O-, Q-, and S- branch spectra are collected simultaneously, with high spectral and spatial resolution, and within a single-laser-shot. The relative intensity of the rotational and vibrational signals can be tuned arbitrarily using polarization techniques. The ultrashort 7 fs pump and Stokes pulses are automatically overlapped temporally and spatially using a two-beam CARS technique, and the crossed probe beam allows for excellent spatial sectioning of the probed location.

Bohlin, Alexis; Kliewer, Christopher J., E-mail: cjkliew@sandia.gov [Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550 (United States)

2014-01-20T23:59:59.000Z

444

Theoretical approach for optical response in electrochemical systems: Application to electrode potential dependence of surface-enhanced Raman scattering  

SciTech Connect (OSTI)

We propose a theoretical approach for optical response in electrochemical systems. The fundamental equation to be solved is based on a time-dependent density functional theory in real-time and real-space in combination with its finite temperature formula treating an electrode potential. Solvation effects are evaluated by a dielectric continuum theory. The approach allows us to treat optical response in electrochemical systems at the atomistic level of theory. We have applied the method to surface-enhanced Raman scattering (SERS) of 4-mercaptopyridine on an Ag electrode surface. It is shown that the SERS intensity has a peak as a function of the electrode potential. Furthermore, the real-space computational approach facilitates visualization of variation of the SERS intensity depending on an electrode potential.

Iida, Kenji; Noda, Masashi; Nobusada, Katsuyuki, E-mail: nobusada@ims.ac.jp [Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Okazaki 444-8585 (Japan)

2014-09-28T23:59:59.000Z

445

Broadband infrared and Raman probes of excited-state vibrational molecular dynamics; Simulation protocols based on loop diagram  

E-Print Network [OSTI]

Vibrational motions in electronically excited states can be observed by either time and frequency resolved infrared absorption or by off resonant stimulated Raman techniques. Multipoint correlation function expressions are derived for both signals. Three representations for the signal which suggest different simulation protocols are developed. These are based on the forward and the backward propagation of the wavefunction, sum over state expansion using an effective vibration Hamiltonian and a semiclassical treatment of a bath. We show that the effective temporal ($\\Delta t$) and spectral ($\\Delta\\omega$) resolution of the techniques is not controlled solely by experimental knobs but also depends on the system dynamics being probed. The Fourier uncertainty $\\Delta\\omega\\Delta t>1$ is never violated.

Konstantin E. Dorfman; Benjamin P. Fingerhut; Shaul Mukamel

2013-05-23T23:59:59.000Z

446

Noise sources and competition between stimulated Brillouin and Raman scattering: A one-dimensional steady-state approach  

SciTech Connect (OSTI)

A 1D steady-state model is developed to deal with stimulated scattering processes. The volume and boundary noise sources for scattered light are discussed in detail. Our results indicate that the boundary noise sources may play a significant role in estimating the reflectivity of stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS). With the capability of our model to deal with broadband scattered light, we find that pump depletion could be the main reason to the anti-correlation between SBS and SRS versus electron density observed in experiments. A simple method is proposed to phenomenologically include the effect of nonlinear saturation mechanisms in our model and reasonable results are obtained.

Gong, Tao [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Li, Zhichao [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)] [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Zhao, Bin; Hu, Guang-yue; Zheng, Jian [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2013-09-15T23:59:59.000Z

447

Development of a Raman spectroscopy technique to detect alternate transportation fuel hydrocarbon intermediates in complex combustion environments.  

SciTech Connect (OSTI)

Spontaneous Raman spectra for important hydrocarbon fuels and combustion intermediates were recorded over a range of low-to-moderate flame temperatures using the multiscalar measurement facility located at Sandia/CA. Recorded spectra were extrapolated to higher flame temperatures and then converted into empirical spectral libraries that can readily be incorporated into existing post-processing analysis models that account for crosstalk from overlapping hydrocarbon channel signal. Performance testing of the developed libraries and reduction methods was conducted through an examination of results from well-characterized laminar reference flames, and was found to provide good agreement. The diagnostic development allows for temporally and spatially resolved flame measurements of speciated hydrocarbon concentrations whose parent is more chemically complex than methane. Such data are needed to validate increasingly complex flame simulations.

Ekoto, Isaac W.; Barlow, Robert S.

2012-12-01T23:59:59.000Z

448

Cost effective nanostructured copper substrates prepared with ultrafast laser pulses for explosives detection using surface enhanced Raman scattering  

SciTech Connect (OSTI)

Ultrafast laser pulses induced surface nanostructures were fabricated on a copper (Cu) target through ablation in acetone, dichloromethane, acetonitrile, and chloroform. Surface morphological information accomplished from the field emission scanning electron microscopic data demonstrated the diversities of ablation mechanism in each case. Fabricated Cu substrates were utilized exultantly to investigate the surface plasmon (localized and propagating) mediated enhancements of different analytes using surface enhance Raman scattering (SERS) studies. Multiple utility of these substrates were efficiently demonstrated by collecting the SERS data of Rhodamine 6G molecule and two different secondary explosive molecules such as 5-amino-3-nitro-l,2,4-triazole and trinitrotoluene on different days which were weeks apart. We achieved significant enhancement factors of >10{sup 5} through an easily adoptable cleaning procedure.

Hamad, Syed [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Podagatlapalli, G. Krishna; Soma, Venugopal Rao, E-mail: svrsp@uohyd.ernet.in, E-mail: soma-venu@yahoo.com [Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Mohiddon, Md. Ahamad [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)

2014-06-30T23:59:59.000Z

449

Li{sub 2}Si{sub 3}O{sub 7}: Crystal structure and Raman spectroscopy  

SciTech Connect (OSTI)

The crystal structure of metastable Li{sub 2}Si{sub 3}O{sub 7} was determined from single crystal X-ray diffraction data. The orthorhombic crystals were found to adopt space group Pmca with unit cell parameters of a=19.648(3)A, b=5.9969(8)A and c=4.8691(6)A. The content of the cell is Z=4. The obtained structural model was refined to a R-value of 0.035. The structure exhibits silicate sheets, which can be classified as {l_brace}uB,2,1{sub {approx}}{sup 2}{r_brace}[Si{sub 6}O{sub 14}] using the silicate nomenclature of Liebau. The layers are build up from zweier single chains running parallel to c. Raman spectra are presented and compared with other silicates. Furthermore, the structure is discussed versus Na{sub 2}Si{sub 3}O{sub 7}.

Krueger, Hannes [Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck (Austria)], E-mail: Hannes.Krueger@uibk.ac.at; Kahlenberg, Volker [Institute of Mineralogy and Petrography, University of Innsbruck, Innrain 52, 6020 Innsbruck (Austria); Kaindl, Reinhard [Christian-Doppler-Laboratory for Advanced Hard Coatings at the Institute of Mineralogy and Petrography, University of Innsbruck, 6020 Innsbruck (Austria)

2007-03-15T23:59:59.000Z

450

Charge transfer switching in photoexcited Ru(II) porphyrins: A time-resolved resonance Raman and spectroelectrochemical study  

SciTech Connect (OSTI)

The charge transfer (CT) excited states of Ru(II)OEP(Py){sub 2} and Ru(II)TPP(Py){sub 2} (TPP=tetraphenylporphyrin, OEP=octaethylporphyrin, and Py=pyridine) have been investigated by nanosecond time-resolved resonance Raman(TR{sup 3}) spectroscopy. The spectra reveal unexpected differences between the two species. The TR{sup 3} spectrum of [Ru(II)TPP(Py){sub 2}]{sup *} resembles the resonance Raman (RR) spectrum of the RuTPP(Py){sub 2} radical anion. Both spectra show strong enhancement of nontotally symmetric modes, resulting from a Jahn-Teller distortion due to the e{sub g}{sup *} orbital degeneracy. The band frequencies are slightly higher in the CT state than in the radical anion, reflecting the effect of the Ru(II) oxidation. Thus, the TR{sup 3} spectral features support a {sup 3}(d{pi},{pi}{sup *}) excited state assignment, with an electron transferred from Ru(II) to the porphyrin. In contrast, the TR3 spectrum [Ru(II)OEP(Py){sub 2}]{sup *} does not resemble the RR spectra of the Ru(II)OEP radical anion. Rather, it contains totally symmetric modes, at frequencies close to those of Ru(II)OEP(Py){sub 2}. In addition, bound pyridine modes appear at 1208 and 1603 cm{sup -1} in the TR{sup 3} spectrum and they shift upon pyridine perdeuteration. These characteristics imply electron transfer from Ru(II) to bound pyridine, instead of porphyrin, for the CT state of Ru(II)OEP(Py){sub 2}. 38 refs., 11 figs., 4 tabs.

Vitols, S.E.; Kumble, R.; Blackwood, M.E. Jr.; Roman, J.S.; Spiro, T.G. [Princeton Univ., NJ (United States)] [Princeton Univ., NJ (United States)

1996-03-07T23:59:59.000Z

451

RELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BY RESONANT RAMAN  

E-Print Network [OSTI]

RELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BYRELATIVE CHIRAL ABUNDANCES OF CARBON NANOTUBES DETERMINED BY RESONANT RAMAN SPECTROSCOPY USING A TUNABLE DYE LASERRESONANT

Mellor-Crummey, John

452

Development of an Integrated Raman and Turbidity Fiber Optic Sensor for the In-Situ Analysis of High Level Nuclear Waste - 13532  

SciTech Connect (OSTI)

Stored nuclear waste must be retrieved from storage, treated, separated into low- and high-level waste streams, and finally put into a disposal form that effectively encapsulates the waste and isolates it from the environment for a long period of time. Before waste retrieval can be done, waste composition needs to be characterized so that proper safety precautions can be implemented during the retrieval process. In addition, there is a need for active monitoring of the dynamic chemistry of the waste during storage since the waste composition can become highly corrosive. This work describes the development of a novel, integrated fiber optic Raman and light scattering probe for in situ use in nuclear waste solutions. The dual Raman and turbidity sensor provides simultaneous chemical identification of nuclear waste as well as information concerning the suspended particles in the waste using a common laser excitation source. (authors)

Gasbarro, Christina; Bello, Job [EIC Laboratories, Inc., 111 Downey St., Norwood, MA, 02062 (United States)] [EIC Laboratories, Inc., 111 Downey St., Norwood, MA, 02062 (United States); Bryan, Samuel; Lines, Amanda; Levitskaia, Tatiana [Pacific Northwest National Laboratory, PO Box 999, Richland, WA, 99352 (United States)] [Pacific Northwest National Laboratory, PO Box 999, Richland, WA, 99352 (United States)

2013-07-01T23:59:59.000Z

453

Enhancement of Raman Light Scattering in Dye-Labeled Rat Glioma Cells by Langmuir-Blodgett CNT-Bundles Arranged on Metal-Containing Conducting Polymer Film  

E-Print Network [OSTI]

We have fabricated layered nanocomposite consisting of a nanoporous anodic alumina sublayer (AOA), an ultrathin metal-containing polymer Langmuir-Blodgett (LB) film coating AOA, and multi-walled carbon nanotube (MCNT) - bundles which are arranged on the LB-film. MCNTs were preliminarily chemically modified by carboxyl groups and functionalized by stearic acid. We have experimentally observed an enhancement of Raman light scattering on surface plasmons in the LB-monolayers. This enhancement is due to charge and energy transfer. We demonstrate that propidium iodide (PI) fluorescence is quenched by the MCNT-bundles. A method of two-dimensional system imaging based on the MCNT-enhanced Raman spectroscopy has been proposed. This method has been applied to visualize focal adhesion sites on membranes of living PI-labeled rat glioma cells.

Egorov, A S; Grushevskaya, H V; Krot, V I; Krylova, N G; Lipnevich, I V; Orekhovskaya, T I; Shulitsky, B G

2015-01-01T23:59:59.000Z

454

Experimental and theoretical study of red-shifted solitonic resonant radiation in photonic crystal fibers and generation of radiation seeded Raman solitons  

E-Print Network [OSTI]

The red shifted solitonic resonant radiation is a fascinating phase matching phenomenon that occurs when an optical pulse, launched in the normal dispersion regime of photonic crystal fiber, radiates across the zero dispersion wavelength. The formation of such phase-matched radiation is independent of the generation of any optical soliton and mainly governed by the leading edge of input pump which forms a shock front. The radiation is generated at the anomalous dispersion regime and found to be confined both in time and frequency domain. We experimentally investigate the formation of such radiations in photonic crystal fibers with detailed theoretical analysis. Our theoretical predictions corroborate well with experimental results. Further we extend our study for long length fiber and investigate the interplay between red-shifted solitonic resonant radiation and intrapulse Raman scattering (IPRS). It is observed that series of radiation-seeded Raman solitons are generated in anomalous dispersion regime.

Bose, Surajit; Chattopadhyay, Rik; Pal, Mrinmay; Bhadra, Shyamal K

2015-01-01T23:59:59.000Z

455

Investigation of Temperature Dependent Optical Modes in GexAs35-xSe65 Thin Films: Structure Specific Raman, FIR and Optical Absorption Spectroscopy  

E-Print Network [OSTI]

In this article, we present a comprehensive study of temperature and composition dependent Raman spectroscopy of GexAs35-xSe65 thin films to understand different structural units responsible for optical properties. Strikingly, our experimental results uncover the ratio of GeSe4/2 tetrahedral and AsSe3/2 pyramidal units in GexAs35-xSe65 thin films and their linear scaling relationship with temperature and x. An important notable outcome of our study is the formation of Se8 rings at lower temperatures. Our experimental results further provide interesting optical features, thermally and compositionally tunable optical absorption spectra. Detailed structure specific FIR data at room temperature also present direct information on the structural units in consistent with Raman data. We foresee that our studies are useful in determining the lightinduced response of these films and also for their potential applications in optics and optoelectronics.

Khan, Pritam; Joshy, Abin; Sathe, Vasant; Deshpande, Uday; Adarsh, K V

2015-01-01T23:59:59.000Z

456

Raman Investigation of The Uranium Compounds U3O8, UF4, UH3 and UO3 under Pressure at Room Temperature  

SciTech Connect (OSTI)

Our current state-of-the-art X-ray diffraction experiments are primarily sensitive to the position of the uranium atom. While the uranium - low-Z element bond (such as U-H or U-F) changes under pressure and temperature the X-ray diffraction investigations do not reveal information about the bonding or the stoichiometry. Questions that can be answered by Raman spectroscopy are (i) whether the bonding strength changes under pressure, as observed by either blue- or red-shifted peaks of the Raman active bands in the spectrum and (ii) whether the low-Z element will eventually be liberated and leave the host lattice, i.e. do the fluorine, oxygen, or hydrogen atoms form dimers after breaking the bond to the uranium atom. Therefore Raman spectra were also collected in the range where those decomposition products would appear. Raman is particularly well suited to these types of investigations due to its sensitivity to trace amounts of materials. One challenge for Raman investigations of the uranium compounds is that they are opaque to visible light. They absorb the incoming radiation and quickly heat up to the point of decomposition. This has been dealt with in the past by keeping the incoming laser power to very low levels on the tens of milliWatt range consequently affecting signal to noise. Recent modern investigations also used very small laser spot sizes (micrometer range) but ran again into the problem of heating and chemical sensitivity to the environment. In the studies presented here (in contrast to all other studies that were performed at ambient conditions only) we employ micro-Raman spectroscopy of samples situated in a diamond anvil cell. This increases the trustworthiness of the obtained data in several key-aspects: (a) We surrounded the samples in the DAC with neon as a pressure transmitting medium, a noble gas that is absolutely chemically inert. (b) Through the medium the sample is thermally heat sunk to the diamond anvils, diamond of course possessing the very best heat conductivity of any material. Therefore local heating and decomposition are avoided, a big challenge with other approaches casting doubts on their results. (c) This in turn benefits the signal/noise ratio tremendously since the Raman features of uranium-compounds are very small. The placement of the samples in DACs allows for higher laser powers to impinge on the sample spot while keeping the spot-size larger than in previous studies and keep the samples from heating up. Raman spectroscopy is a very sensitive non-invasive technique and we will show that it is even possible to distinguish the materials by their origin / manufacturer as we have studied samples from Cameco (Canada) and IBI-Labs (US-Florida) and can compare with ambient literature data for samples from Strem (US-MA) and Areva (Pierrelatte, France).

Lipp, M J; Jenei, Z; Park-Klepeis, J; Evans, W J

2011-12-15T23:59:59.000Z

457

Determination of the structural changes by Raman and {sup 13}C CP/MAS NMR spectroscopy on native corn starch with plasticizers  

SciTech Connect (OSTI)

The plasticizing - antiplasticizing effect of water and glycerol contents on native corn starch samples is investigated by FT-Raman and {sup 13}C CP/MAS NMR spectroscopy. The presence of both amorphous and crystalline structural phases was evidenced in pure native corn starch and also in the samples containing plasticizers. Among the crystalline starch structures, the A- and V- types were suggested by CP/MAS NMR spectra.

Cozar, O. [Academy of Romanian Scientists, Splaiul Independentei 54, 050094, Bucharest, Romania and National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch (Romania)] [Academy of Romanian Scientists, Splaiul Independentei 54, 050094, Bucharest, Romania and National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch (Romania); Filip, C.; Tripon, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Cioica, N.; Co?a, C.; Nagy, E. M. [National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch, RO-400458 Cluj-Napoca (Romania)] [National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch, RO-400458 Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

458

Relic Crystal-Lattice Effects on Raman Compression of Powerful X-Ray Pulses in Plasmas V. M. Malkin and N. J. Fisch  

E-Print Network [OSTI]

.38.ÿr, 41.60.Cr, 42.55.Vc, 42.65.Re New mJ x-ray laser technologies [1­3] might produce attosecond laser optical laser technologies [4,5]. The currently projected durations of powerful x-ray pulsesRelic Crystal-Lattice Effects on Raman Compression of Powerful X-Ray Pulses in Plasmas V. M. Malkin

459

Plasmon Mapping in Metallic Nanostructures and its Application to Single Molecule Surface Enhanced Raman Scattering: Imaging Electromagnetic Hot-Spots and Analyte Location  

SciTech Connect (OSTI)

A major component of this proposal is to elucidate the connection between optical and electron excitation of plasmon modes in metallic nanostructures. These accomplishments are reported: developed a routine protocol for obtaining spatially resolved, low energy EELS spectra, and resonance Rayleigh scattering spectra from the same nanostructures.; correlated optical scattering spectra and plasmon maps obtained using STEM/EELS.; and imaged electromagnetic hot spots responsible for single-molecule surface-enhanced Raman scattering (SMSERS).

Camden, Jon P

2013-07-16T23:59:59.000Z

460

Characterization of Defects in N-type 4H-SiC After High-Energy N Ion Implantation by RBS-Channeling and Raman Spectroscopy  

SciTech Connect (OSTI)

Implantation with 1 MeV N ions was performed at room temperature in n-type 4H-SiC(0001) to four implantation fluences (or doses in dpa (displacements per atom) at the damage peak) of 1.5×1013(0.0034), 7.8×1013(0.018), 1.5×1014(0.034), and 7.8×1014(0.18) ions/cm2, respectively. The evolution of disorder was studied using Rutherford backscattering spectrometry in channeling mode (RBS-C) and Raman spectroscopy. The disorder in the Si sub-lattice was found to be less than 10% for the dpa of 0.0034 and 0.0178 and increased to 40% and 60% for the dpa of 0.034 and 0.178 respectively. Raman Spectroscopy was performed using a green laser of wavelength 532 nm as excitation source. The normalized Raman Intensity, In shows disorder of 41%, 69%, 77% and 100% for the dpa of 0.0034, 0.017, 0.034 and 0.178 respectively. In this paper, the characterizations of the defects produced due to the Nitrogen implantation in 4H-SiC are presented and the results are discussed.

Kummari, Venkata C.; Reinert, Tilo; Jiang, Weilin; McDaniel, Floyd D.; Rout, Bibhudutta

2014-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "raman lidar profiles-temperature" from the National Library of EnergyBeta (NLEBeta).
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461

Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO{sub 2} films with M1 and M2 phases  

SciTech Connect (OSTI)

Structural and electronic phase transitions behavior of two polycrystalline VO{sub 2} films, one with pure M1 phase and the other with pure M2 phase at room temperature, were investigated by temperature-controlled Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS). We observed characteristic transient dynamics in which the Raman modes at 195?cm{sup ?1} (V-V vibration) and 616?cm{sup ?1} (V-O vibration) showed remarkable hardening along the temperature in M1 phase film, indicating the rearrangements of V-V pairs and VO{sub 6} octahedra. It was also shown that the M1 Raman mode frequency approached those of invariant M2 peaks before entering rutile phase. In UPS spectra with high energy resolution of 0.03?eV for the M2 phase film, narrower V{sub 3d} band was observed together with smaller gap compared to those of M1 phase film, supporting the nature of Mott insulator of M2 phase even in the polycrystalline film. Cooperative behavior of lattice rearrangements and electronic phase transition was suggested for M1 phase film.

Okimura, Kunio, E-mail: okifn@keyaki.cc.u-tokai.ac.jp; Hanis Azhan, Nurul [Graduate School of Engineering, Tokai University, Hiratsuka 259-1292 (Japan); Hajiri, Tetsuya [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kimura, Shin-ichi [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871 (Japan); Zaghrioui, Mustapha; Sakai, Joe [GREMAN, UMR 7347 CNRS, Université François Rabelais de Tours, Parc de Grandmont, 37200 Tours (France)

2014-04-21T23:59:59.000Z

462

Simulating one-photon absorption and resonance Raman scattering spectra using analytical excited state energy gradients within time-dependent density functional theory  

SciTech Connect (OSTI)

A parallel implementation of analytical time-dependent density functional theory gra- dients is presented for the quantum chemistry program NWChem. The implementation is based on the Lagrangian approach developed by Furche and Ahlrichs. To validate our implementation, we first calculate the Stokes shifts for a range of organic dye molecules using a diverse set of exchange-correlation functionals (traditional density functionals, global hybrids and range-separated hybrids) followed by simulations of the one-photon absorption and resonance Raman scattering spectrum of the phenoxyl radical, the well-studied dye molecule rhodamine 6G and a molecular host-guest complex (TTF?CBPQT4+). The study of organic dye molecules illustrates that B3LYP and CAM-B3LYP generally give the best agreement with experimentally determined Stokes shifts unless the excited state is a charge transfer state. Absorption, resonance Raman, and fluorescence simulations for the phenoxyl radical indicate that explicit solvation may be required for accurate characterization. For the host-guest complex and rhodamine 6G, it is demonstrated that absorption spectra can be simulated in good agreement with experiment for most exchange-correlation functionals. However, because one-photon absorption spectra generally lack well-resolved vibrational features, resonance Raman simulations are necessary to evaluate the accuracy of the exchange-correlation functional for describing a potential energy surface.

Silverstein, Daniel W.; Govind, Niranjan; van Dam, Hubertus JJ; Jensen, Lasse

2013-12-10T23:59:59.000Z

463

A New Methodology for Characterization of Environmentally Important Radionuclide Species Via Surface-Enhanced Raman Scattering (SERS)  

SciTech Connect (OSTI)

Selective and sensitive detection and characterization of radionuclide contaminants in subsurface environments is essential to safely and to cost-effectively locate, treat, isolate or destroy contaminants encountered in DOE's environmental cleanup activity. Currently, techniques for monitoring and characterizing radionuclides rely primarily on liquid scintillation counting, ICP-MS and some limited use of the spectrofluorimetry based on fluorescence of radionuclide species under laser or UV excitation. These techniques require chemical handling, e.g., the use of complexing media, scintillation cocktails and phosphoric acids, in order to enhance signals. Furthermore, only fluorescent radionuclides (U22O+, Cm(III) and Am(III)) can be detected by the last technique. Many environmentally-important radionuclides such as plutonium, neptunium and technetium species have no strong fluorescence signals and, therefore, can not be characterized via fluorescence spectroscopy. The research presented serves to replace existing radionuclide-detection techniques through the development of a novel surface enhanced Raman scattering (SERS) spectroscopy to selectively and sensitively monitor and characterize the chemical speciation of radionuclides at trace levels. The SERS technique permits both of these measurements to be made simultaneously and results in significant improvement over current methods in reducing time of analysis, cost and sample manipulation.

Dai, Sheng; Bao, Li-Li; Mahurin, Shannon; Gu, Baohua

2004-03-31T23:59:59.000Z

464

Realisation of four-wave mixing phase matching for frequency components at intracavity stimulated Raman scattering in a calcite crystal  

SciTech Connect (OSTI)

The possibilities of implementing four-wave mixing (FWM) phase matching at stimulated Raman scattering (SRS) in a birefringent SRS-active crystal placed in a cavity with highly reflecting mirrors have been theoretically and experimentally investigated. Phase-matching angles providing conditions for five types of phase matching are determined for a calcite crystal. These types are characterised by different combinations of polarisation directions for the interacting waves and ensure FWM generation of either an anti-Stokes wave or the second Stokes SRS component. In agreement with the calculation results, low-threshold generation of the second Stokes SRS component with a wavelength 0.602 {mu}m was observed at angles of incidence on a calcite crystal of 4.8 Degree-Sign and 18.2 Degree-Sign , under SRS pumping at a wavelength of 0.532 {mu}m. This generation is due to the FWM coupling of the first and second Stokes SRS components with the SRS-pump wave. (nonlinear optical phenomena)

Smetanin, Sergei N; Fedin, Aleksandr V; Shurygin, Anton S

2013-06-30T23:59:59.000Z

465

Microtopographic characterization of ice-wedge polygon landscape in Barrow, Alaska: a digital map of troughs, rims, centers derived from high resolution (0.25 m) LiDAR data  

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

The dataset represents microtopographic characterization of the ice-wedge polygon landscape in Barrow, Alaska. Three microtopographic features are delineated using 0.25 m high resolution digital elevation dataset derived from LiDAR. The troughs, rims, and centers are the three categories in this classification scheme. The polygon troughs are the surface expression of the ice-wedges that are in lower elevations than the interior polygon. The elevated shoulders of the polygon interior immediately adjacent to the polygon troughs are the polygon rims for the low center polygons. In case of high center polygons, these features are the topographic highs. In this classification scheme, both topographic highs and rims are considered as polygon rims. The next version of the dataset will include more refined classification scheme including separate classes for rims ad topographic highs. The interior part of the polygon just adjacent to the polygon rims are the polygon centers.

Gangodagamage, Chandana; Wullschleger, Stan

466

Microtopographic characterization of ice-wedge polygon landscape in Barrow, Alaska: a digital map of troughs, rims, centers derived from high resolution (0.25 m) LiDAR data  

SciTech Connect (OSTI)

The dataset represents microtopographic characterization of the ice-wedge polygon landscape in Barrow, Alaska. Three microtopographic features are delineated using 0.25 m high resolution digital elevation dataset derived from LiDAR. The troughs, rims, and centers are the three categories in this classification scheme. The polygon troughs are the surface expression of the ice-wedges that are in lower elevations than the interior polygon. The elevated shoulders of the polygon interior immediately adjacent to the polygon troughs are the polygon rims for the low center polygons. In case of high center polygons, these features are the topographic highs. In this classification scheme, both topographic highs and rims are considered as polygon rims. The next version of the dataset will include more refined classification scheme including separate classes for rims ad topographic highs. The interior part of the polygon just adjacent to the polygon rims are the polygon centers.

Gangodagamage, Chandana; Wullschleger, Stan

2014-07-03T23:59:59.000Z

467

Application of surface-enhanced Raman scattering (SERS) for the identification of anthraquinone dyes used in works of art  

SciTech Connect (OSTI)

Surface-enhanced Raman scattering (SERS) was investigated for applications in the analysis of anthraquinone dyes used in works of art. Two SERS procedures were developed and evaluated with three frequently used anthraquinone dyes, alizarin, carminic acid and lac dye. The first procedure involves coating a layer of silver nanoparticles directly on pieces of filter paper stained with the dyes of interest by thermal evaporation to induce SERS effect. In the second procedure, a SERS-active Ag-Al{sub 2}O{sub 3} substrate was prepared by spin-coating an alumina-nanoparticle layer onto a glass slide to provide the nanostructure of the substrate, followed by thermally evaporating a layer of silver nanoparticles on top of the alumina layer. Aliquots of dye solutions were delivered onto this substrate to be analyzed. Intense SERS spectra characteristic of alizarin, carminic acid and lac dye were obtained using both SERS procedures. The effects of two parameters, the concentration of the alumina suspension and the thickness of the silver nanoparticle layer on the performance of the Ag-Al{sub 2}O{sub 3} substrate were examined with alizarin as the model compound. Comparative studies were conducted between the Ag-Al{sub 2}O{sub 3} substrate and the SERS substrate prepared using Tollens reaction. The Ag-Al{sub 2}O{sub 3} substrate was shown to offer larger enhancement and improved reproducibility than the Tollens substrates. Finally, the potential applicability of the Ag-Al{sub 2}O{sub 3} substrate for the analysis of real artifact objects was illustrated by the identification of alizarin extracted from a small piece of textile dyed using traditional methods and materials. The limit of detection for alizarin was estimated to be 7 x 10{sup -15} g from tests performed on solutions of known concentration.

Chen, Kui [ORNL; Leona, Marco [ORNL; Yan, Fei [ORNL; Wabuyele, Musundi B [ORNL; Vo Dinh, Tuan [ORNL

2006-04-01T23:59:59.000Z

468

Study on the effect of heat treatment and gasification on the carbon structure of coal chars and metallurgical cokes using fourier transform Raman spectroscopy  

SciTech Connect (OSTI)

Differences in the development of carbon structures between coal chars and metallurgical cokes during high-temperature reactions have been investigated using Raman spectroscopy. These are important to differentiate between different types of carbons in dust recovered from the top gas of the blast furnace. Coal chars have been prepared from a typical injectant coal under different heat-treatment conditions. These chars reflected the effect of peak temperature, residence time at peak temperature, heating rate and pressure on the evolution of their carbon structures. The independent effect of gasification on the development of the carbon structure of a representative coal char has also been studied. A similar investigation has also been carried out to study the effect of heat-treatment temperature (from 1300 to 2000{sup o}C) and gasification on the carbon structure of a typical metallurgical coke. Two Raman spectral parameters, the intensity ratio of the D band to the G band (I{sub D}/I{sub G}) and the intensity ratio of the valley between D and G bands to the G band (I{sub V}/I{sub G}), have been found useful in assessing changes in carbon structure. An increase in I{sub D}/I{sub G} indicates the growth of basic graphene structural units across the temperature range studied. A decrease in I{sub V}/I{sub G} appears to suggest the elimination of amorphous carbonaceous materials and ordering of the overall carbon structure. The Raman spectral differences observed between coal chars and metallurgical cokes are considered to result from the difference in the time-temperature history between the raw injectant coal and the metallurgical coke and may lay the basis for differentiation between metallurgical coke fines and coal char residues present in the dust carried over the top of the blast furnace. 41 refs., 17 figs., 3 tabs.

S. Dong; P. Alvarez; N. Paterson; D.R. Dugwell; R. Kandiyoti [Imperial College London, London (United Kingdom). Department of Chemical Engineering

2009-03-15T23:59:59.000Z

469

Structural dynamics of phenylisothiocyanate in the light-absorbing excited states: Resonance Raman and complete active space self-consistent field calculation study  

SciTech Connect (OSTI)

The excited state structural dynamics of phenyl isothiocyanate (PITC) after excitation to the light absorbing S{sub 2}(A?), S{sub 6}(A?), and S{sub 7}(A?) excited states were studied by using the resonance Raman spectroscopy and complete active space self-consistent field method calculations. The UV absorption bands of PITC were assigned. The vibrational assignments were done on the basis of the Fourier transform (FT)-Raman and FT-infrared measurements, the density-functional theory computations, and the normal mode analysis. The A-, B-, and C-bands resonance Raman spectra in cyclohexane, acetonitrile, and methanol solvents were, respectively, obtained at 299.1, 282.4, 266.0, 252.7, 228.7, 217.8, and 208.8 nm excitation wavelengths to probe the corresponding structural dynamics of PITC. The results indicated that the structural dynamics in the S{sub 2}(A?), S{sub 6}(A?), and S{sub 7}(A?) excited states were very different. The conical intersection point CI(S{sub 2}/S{sub 1}) were predicted to play important role in the low-lying excited state decay dynamics. Two major decay channels were predicted for PITC upon excitation to the S{sub 2}(A?) state: the radiative S{sub 2,min} ? S{sub 0} transition and the nonradiative S{sub 2} ? S{sub 1} internal conversion via CI(S{sub 2}/S{sub 1}). The differences in the decay dynamics between methyl isothiocyanate and PITC in the first light absorbing excited state were discussed. The role of the intersystem crossing point ISC(S{sub 1}/T{sub 1}) in the excited state decay dynamics of PITC is evaluated.

Ouyang, Bing, E-mail: ouyangbing.zj@foxmail.com; Xue, Jia-Dan, E-mail: jenniexue@126.com; Zheng, Xuming, E-mail: zhengxuming126@126.com, E-mail: zxm@zstu.edu.cn, E-mail: fangwh@dnu.edu.cn [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018 (China)] [Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Fang, Wei-Hai, E-mail: zxm@zstu.edu.cn, E-mail: fangwh@dnu.edu.cn, E-mail: fangwh@dnu.edu.cn [Department of Chemistry, Beijing Normal University, Beijing 100875 (China)] [Department of Chemistry, Beijing Normal University, Beijing 100875 (China)

2014-05-21T23:59:59.000Z

470

Tuning the interaction between propagating and localized surface plasmons for surface enhanced Raman scattering in water for biomedical and environmental applications  

SciTech Connect (OSTI)

With a view to biomedical and environmental applications, we investigate the plasmonic properties of a rectangular gold nanodisk array in water to boost surface enhanced Raman scattering (SERS) effects. To control the resonance wavelengths of the surface plasmon polariton and the localized surface plasmon, their dependence on the array period and diameter in water is studied in detail using a finite difference time domain method. A good agreement is obtained between calculated resonant wavelengths and those of gold nanodisk arrays fabricated using electron beam lithography. For the optimized structure, a SERS enhancement factor of 7.8?×?10{sup 7} is achieved in water experimentally.

Shioi, Masahiko, E-mail: shioi.masahiko@jp.panasonic.com [Device Solutions Center, Panasonic Corporation, 3-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan); Department of Electric and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Jans, Hilde [Interuniversity Microelectronics Center VZW., Kapeldreef 75, 3001 Leuven (Belgium); Lodewijks, Kristof [Interuniversity Microelectronics Center VZW., Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Van Dorpe, Pol; Lagae, Liesbet [Interuniversity Microelectronics Center VZW., Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Kawamura, Tatsuro [Device Solutions Center, Panasonic Corporation, 3-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan)

2014-06-16T23:59:59.000Z

471

Publisher's Note: Correlation of photon pairs from the double Raman amplifier: Generalized analytical quantum Langevin theory (vol 75, pg 013820, 2007)  

E-Print Network [OSTI]

Publisher?s Note: Correlation of photon pairs from the double Raman amplifier: Generalized analytical quantum Langevin theory [Phys. Rev. A 75, 013820 (2007)] C. H. Raymond Ooi, Qingqing Sun, M. Suhail Zubairy, and Marlan O. Scully #1;Received 1... February 2007; published 6 February 2007#2; DOI: 10.1103/PhysRevA.75.029902 PACS number#1;s#2;: 42.50.Dv, 42.50.Gy, 42.50.Lc, 03.67.Mn, 99.10.Fg This paper was published online on 31 January 2007 without all of the author?s corrections incorporated...

Ooi, C. H. Raymond; Sun, Qingqing; Zubairy, M. Suhail; Scully, Marlan O.

2007-01-01T23:59:59.000Z

472

Phase transformation in multiferroic Bi{sub 5}Ti{sub 3}FeO{sub 15} ceramics by temperature-dependent ellipsometric and Raman spectra: An interband electronic transition evidence  

SciTech Connect (OSTI)

Thermal evolution and an intermediate phase between ferroelectric orthorhombic and paraelectric tetragonal phase of multiferroic Bi{sub 5}Ti{sub 3}FeO{sub 15} ceramic have been investigated by temperature-dependent spectroscopic ellipsometry and Raman scattering. Dielectric functions and interband transitions extracted from the standard critical-point model show two dramatic anomalies in the temperature range of 200–873?K. It was found that the anomalous temperature dependence of electronic transition energies and Raman mode frequencies around 800?K can be ascribed to intermediate phase transformation. Moreover, the disappearance of electronic transition around 3?eV at 590?K is associated with the conductive property.

Jiang, P. P.; Duan, Z. H.; Xu, L. P.; Zhang, X. L.; Li, Y. W.; Hu, Z. G., E-mail: zghu@ee.ecnu.edu.cn; Chu, J. H. [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China)

2014-02-28T23:59:59.000Z

473

Spin-phonon interactions of multiferroic Bi{sub 4}Ti{sub 3}O{sub 12}-BiFeO{sub 3} ceramics: Low-temperature Raman scattering and infrared reflectance spectra investigations  

SciTech Connect (OSTI)

Optical phonons of multiferroic Bi{sub 4}Ti{sub 3}O{sub 12}-BiFeO{sub 3} ceramic have been investigated by low temperature Raman scattering and infrared reflectance spectra. Anomalies at about 85?K can be observed from the temperature dependence of the Raman and infrared modes, which arise from spin-phonon interaction during antiferromagnetic to paramagnetic phase transition. It was found that the change of exchange interaction in magnetic phase transition can be induced by Fe-O-Fe octahedral tilting driven from the A-site atoms. Moreover, ferroelectricity-related displacement of Bismuth atoms suggests the coupling of magnetic and ferroelectric orders.

Jiang, P. P.; Zhang, X. L.; Chang, P.; Hu, Z. G., E-mail: zghu@ee.ecnu.edu.cn; Bai, W.; Li, Y. W.; Chu, J. H. [Department of Electronic Engineering, Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200241 (China)

2014-04-14T23:59:59.000Z

474

Phonon renormalization and Raman spectral evolution through amorphous to crystalline transitions in Sb{sub 2}Te{sub 3} thin films  

SciTech Connect (OSTI)

A symmetry specific phonon mode renormalization is observed across an amorphous to crystalline phase transformation in thin films of the topological material Sb{sub 2}Te{sub 3} using Raman spectroscopy. We present evidence for local crystalline symmetry in the amorphous state, eventhough, the q?=?0 Raman selection rule is broken due to strong structural disorder. At crystallization, the in-plane polarized (E{sub g}{sup 2}) mode abruptly sharpens while the out-of-plane polarized (A{sub 1g}) modes are only weakly effected. This effect unique to the E{sub g} symmetry is exceptional considering that polarized spectra and comparison of the single phonon density of states between the amorphous and crystalline phases suggest that short range order of the amorphous phase is, on the average, similar to that of the crystalline material while electrical transport measurements reveal a sharp insulator-to-metal transition. Our findings point to the important role of anisotropic disorder affecting potential applications of topological and phase-change based electronics.

Secor, Jeff; Zhao, Lukas; Krusin-Elbaum, Lia [The Graduate Center, CUNY, New York, New York 10016 (United States); Department of Physics, The City College of New York, CUNY, New York, New York 10031 (United States); Harris, Matt A.; Deng, Haiming [Department of Physics, The City College of New York, CUNY, New York, New York 10031 (United States); Raoux, Simone [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

2014-06-02T23:59:59.000Z

475

Raman spectra of R{sub 2}O{sub 3} (R—rare earth) sesquioxides with C-type bixbyite crystal structure: A comparative study  

SciTech Connect (OSTI)

Raman spectra of R{sub 2}O{sub 3} (R—Sc, Er, Y, Ho, Gd, Eu, and Sm) powders with C-type bixbyite crystal structure are measured. With the help of these data and ones, previously published for other oxides from the same structural family, general dependencies of the frequencies of the Raman peaks on the cubic crystal unit cell parameter are constructed. Using these dependencies and knowing the symmetry of the peaks for one of the oxides, determined from previous single-crystal measurements, it is possible to find out the symmetry of the peaks from the spectra of all compounds. It was found that the frequency of the six lowest frequency peaks scales with the square root of the mass of the rare earth showing that mainly R ions take part in these vibrations. These results agree with performed here lattice dynamical calculations. The anomalous softening of the frequency of some peaks in the spectra of Eu{sub 2}O{sub 3} is discussed.

Abrashev, M. V., E-mail: mvabr@phys.uni-sofia.bg [Instituto de Física, UFRGS, Porto Alegre, 91501-970 Rio Grande do Sul (Brazil); Faculty of Physics, University of Sofia, BG-1164 Sofia (Bulgaria); Todorov, N. D. [Faculty of Physics, University of Sofia, BG-1164 Sofia (Bulgaria); Geshev, J. [Instituto de Física, UFRGS, Porto Alegre, 91501-970 Rio Grande do Sul (Brazil)

2014-09-14T23:59:59.000Z

476

In situ apparatus for the study of clathrate hydrates relevant to solar system bodies using synchrotron X-ray diffraction and Raman spectroscopy  

E-Print Network [OSTI]

Clathrate hydrates are believed to play a significant role in various solar system environments, e.g. comets, and the surfaces and interiors of icy satellites, however the structural factors governing their formation and dissociation are poorly understood. We demonstrate the use of a high pressure gas cell, combined with variable temperature cooling and time-resolved data collection, to the in situ study of clathrate hydrates under conditions relevant to solar system environments. Clathrates formed and processed within the cell are monitored in situ using synchrotron X-ray powder diffraction and Raman spectroscopy. X-ray diffraction allows the formation of clathrate hydrates to be observed as CO2 gas is applied to ice formed within the cell. Complete conversion is obtained by annealing at temperatures just below the ice melting point. A subsequent rise in the quantity of clathrate is observed as the cell is thermally cycled. Four regions between 100-5000cm-1 are present in the Raman spectra that carry feature...

Day, Sarah J; Evans, Aneurin; Parker, Julia E

2015-01-01T23:59:59.000Z

477

Direct Growth Graphene on Cu Nanoparticles by Chemical Vapor Deposition as Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine  

E-Print Network [OSTI]

We present a graphene/Cu nanoparticle hybrids (G/CuNPs) system as a surface-enhanced Raman scattering (SERS) substrate for adenosine detection. The Cu nanoparticles wrapped around a monolayer graphene shell were directly synthesized on flat quartz by chemical vapor deposition in a mixture of methane and hydrogen. The G/CuNPs showed an excellent SERS enhancement activity for adenosine. The minimum detected concentration of the adenosine in serum was demonstrated as low as 5 nM, and the calibration curve showed a good linear response from 5 to 500 nM. The capability of SERS detection of adenosine in real normal human urine samples based on G/CuNPs was also investigated and the characteristic peaks of adenosine were still recognizable. The reproducible and the ultrasensitive enhanced Raman signals could be due to the presence of an ultrathin graphene layer. The graphene shell was able to enrich and fix the adenosine molecules, which could also efficiently maintain chemical and optical stability of G/CuNPs. Based...

Xu, Shicai; Jiang, Shouzhen; Wang, Jihua; Wei, Jie; Xu, Shida; Liu, Hanping

2015-01-01T23:59:59.000Z

478

Raman Nanometrology of Graphene.  

E-Print Network [OSTI]

??Graphene is a two-dimensional honey-comb lattice of carbon atoms with very unusual electron energy dispersion. Since its recent micromechanical isolation and measurements, graphene attracted tremendous… (more)

Calizo, Irene Gonzales

2009-01-01T23:59:59.000Z

479

VOLUME 84, NUMBER 17 P H Y S I C A L R E V I E W L E T T E R S 24 APRIL 2000 Bose-Stimulated Raman Adiabatic Passage in Photoassociation  

E-Print Network [OSTI]

a degenerate molecular gas (MBEC) from an already Bose-condensed sample of atoms [4­6]. Photoassociation (PA two-color photoassociation of a Bose-Einstein condensate, focusing on stimulated Raman adiabatic element for an atomic condensate, and photoassociative STIRAP turns out to be a viable mechanism

Javanainen, Juha

480

Solenoid-free Plasma Start-up in NSTX using Transient CHI R. Raman 1), T.R. Jarboe 1), B.A. Nelson 1), D. Mueller 2), M.G. Bell 2), R. Bell 1),  

E-Print Network [OSTI]

1 Solenoid-free Plasma Start-up in NSTX using Transient CHI R. Raman 1), T.R. Jarboe 1), B sustainment and ramp-up of the toroidal plasma current. In these discharges, the central Ohmic transformer by CHI. The coupled discharges have ramped up to >700 kA and transitioned into an H-mode demonstrating

Princeton Plasma Physics Laboratory

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481

An Assessment of MultiAngle Imaging SpectroRadiometer (MISR) Stereo-Derived Cloud Top Heights and cloud top winds using ground-based radar, lidar, and microwave radiometers  

SciTech Connect (OSTI)

Clouds are of tremendous importance to climate because of their direct radiative effects and because of their role in atmospheric dynamics and the hydrological cycle. The value of satellite imagery in monitoring cloud properties on a global basis can hardly be understated. One cloud property that satellites are in an advantageous position to monitor is cloud top height. Cloud top height retrievals are especially important for MISR because the derived height field is used to co-register the measured radiances. In this presentation we show the results of an ongoing comparison between ground-based millimeter-wave cloud radar and lidar measurements of cloud top and MISR stereo-derived cloud top height. This comparison is based on data from three radar systems located in the U.S Southern Great Plains (Lamont, Oklahoma), the Tropical Western Pacific (Nauru Island) and the North Slope of Alaska (Barrow, Alaska). These radars are operated as part of the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. The MISR stereo height algorithm is performing largely as expected for most optically thick clouds. As with many satellite retrievals, the stereo-height retrieval has difficulty with optically thin clouds or ice clouds with little optical contrast near cloud top.

Marchand, Roger T.; Ackerman, Thomas P.; Moroney, C.

2007-03-17T23:59:59.000Z

482

Development and Deployment of a Compact Eye-Safe Scanning Differential absorption Lidar (DIAL) for Spatial Mapping of Carbon Dioxide for Monitoring/Verification/Accounting at Geologic Sequestration Sites  

SciTech Connect (OSTI)

A scanning differential absorption lidar (DIAL) instrument for monitoring carbon dioxide has been developed. The laser transmitter uses two tunable discrete mode laser diodes (DMLD) operating in the continuous wave (cw) mode with one locked to the online absorption wavelength and the other operating at the offline wavelength. Two in-line fiber optic switches are used to switch between online and offline operation. After the fiber optic switch, an acousto- optic modulator (AOM) is used to generate a pulse train used to injection seed an erbium doped fiber amplifier (EDFA) to produce eye-safe laser pulses with maximum pulse energies of 66 {micro}J, a pulse repetition frequency of 15 kHz, and an operating wavelength of 1.571 {micro}m. The DIAL receiver uses a 28 cm diameter Schmidt-Cassegrain telescope to collect that backscattered light, which is then monitored using a photo-multiplier tube (PMT) module operating in the photon counting mode. The DIAL instrument has been operated from a laboratory environment on the campus of Montana State University, at the Zero Emission Research Technology (ZERT) field site located in the agricultural research area on the western end of the Montana State University campus, and at the Big Sky Carbon Sequestration Partnership site located in north-central Montana. DIAL data has been collected and profiles have been validated using a co-located Licor LI-820 Gas Analyzer point sensor.

Repasky, Kevin

2014-03-31T23:59:59.000Z

483

Thermal stability and long term hydrogen/deuterium release from soft to hard amorphous carbon layers analyzed using in-situ Raman spectroscopy. Comparison with Tore Supra deposits  

E-Print Network [OSTI]

The thermal stability of 200 nm thick plasma enhanced chemical vapor deposited a-C:H and a-C:D layers ranging from soft to hard layers has been studied and compared to that of deposits collected on the Tore Supra tokamak plasma facing components by means of in-situ Raman spectroscopy. Linear ramp heating and long term isotherms (from several minutes to 21 days) have been performed and correlations between spectrometric parameters have been found. The information obtained on the sp 2 clustering has been investigated by comparing the G band shift and the 514 nm photon absorption evolution due to the thermal treatment of the layer. The effects of isotopic substitution have also been investigated.

Pardanaud, C; Giacometti, G; Mellet, N; Pégourié, B; Roubin, P

2015-01-01T23:59:59.000Z

484

Elastic properties, sp{sup 3} fraction, and Raman scattering in low and high pressure synthesized diamond-like boron rich carbides  

SciTech Connect (OSTI)

Dense BC{sub x} phases with high boron concentration are predicted to be metastable, superhard, and conductors or superconductors depending on boron concentration. However, up to this point, diamond-like boron rich carbides BC{sub x} (dl-BC{sub x}) phases have been thought obtainable only through high pressure and high temperature treatment, necessitating small specimen volume. Here, we use electron energy loss spectroscopy combined with transmission electron microscopy, Raman spectroscopy, surface Brillouin scattering, laser ultrasonics (LU) technique, and analysis of elastic properties to demonstrate that low pressure synthesis (chemical vapor deposition) of BC{sub x} phases may also lead to the creation of diamond-like boron rich carbides. The elastic properties of the dl-BC{sub x} phases depend on the carbon sp{sup 2} versus sp{sup 3} content, which decreases with increasing boron concentration, while the boron bonds determine the shape of the Raman spectra of the dl-BC{sub x} after high pressure-high temperature treatment. Using the estimation of the density value based on the sp{sup 3} fraction, the shear modulus ? of dl-BC{sub 4}, containing 10% carbon atoms with sp{sup 3} bonds, and dl-B{sub 3}C{sub 2}, containing 38% carbon atoms with sp{sup 3} bonds, were found to be ??=?19.3?GPa and ??=?170?GPa, respectively. The presented experimental data also imply that boron atoms lead to a creation of sp{sup 3} bonds during the deposition processes.

Zinin, Pavel V.; Burgess, Katherine; Jia, Ruth; Sharma, Shiv; Ming, Li-Chung [Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822 (United States); Liu, Yongsheng [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi'an Shanxi (China); Ciston, Jim [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hong, Shiming [Laboratory of High Pressure Physics, Southwest Jiaotong University, Chengdu, Sichuan (China)

2014-10-07T23:59:59.000Z

485

X-ray diffraction analysis and scanning micro-Raman spectroscopy of structural irregularities and strains deep inside the multilayered InGaN/GaN heterostructure  

SciTech Connect (OSTI)

High-resolution X-ray diffraction analysis and scanning confocal Raman spectroscopy are used to study the spatial distribution of strains in the In{sub x}Ga{sub 1-x}N/GaN layers and structural quality of these layers in a multilayered light-emitting diode structure produced by metal-organic chemical vapor deposition onto (0001)-oriented sapphire substrates. It is shown that elastic strains almost completely relax at the heterointerface between the thick GaN buffer layer and In{sub x}Ga{sub 1-x}N/GaN buffer superlattice. It is established that the GaN layers in the superlattice are in a stretched state, whereas the alloy layers are in a compressed state. In magnitude, the stretching strains in the GaN layers are lower than the compressive strains in the InGaN layers. It is shown that, as compared to the buffer layers, the layers of the superlattice contain a smaller number of dislocations and the distribution of dislocations is more randomly disordered. In micro-Raman studies on scanning through the thickness of the multilayered structure, direct evidence is obtained for the asymmetric gradient distributions of strains and crystal imperfections of the epitaxial nitride layers along the direction of growth. It is shown that the emission intensity of the In{sub x}Ga{sub 1-x}N quantum well is considerably (more than 30 times) higher than the emission intensity of the GaN barrier layers, suggesting the high efficiency of trapping of charge carriers by the quantum well.

Strelchuk, V. V., E-mail: Strelch@isp.kiev.ua; Kladko, V. P.; Avramenko, E. A.; Kolomys, O. F.; Safryuk, N. V.; Konakova, R. V. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine); Yavich, B. S., E-mail: byavich@soptel.ru [ZAO Svetlana-Optoelectronics (Russian Federation); Valakh, M. Ya.; Machulin, V. F.; Belyaev, A. E. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

2010-09-15T23:59:59.000Z

486

Near-resonance enhanced O2 detection for dual-broadband pure rotational coherent anti-Stokes Raman scattering with an ultraviolet-visible setup at 266 nm  

SciTech Connect (OSTI)

Broadband and dual-broadband coherent anti-Stokes Raman scattering (CARS) are widely established tools for nonintrusive gas diagnostics. Up to now the investigations have been mainly performed for electronic nonresonant conditions of the gas species of interest. We report on the enhancement of the O2-N2 detection limit of dual-broadband pure rotational CARS by shifting the wavelength of the narrowband pump laser from the commonly used 532-266 nm. This enhancement is caused when the Schumann-Runge absorption band is approached near 176 nm. The principal concept of this experiment, i.e., covering the Raman resonance with a single- or dual-broadband combination of lasers in the visible range and moving only the narrowband probe laser near or directly into electronic resonant conditions in the UV range, should also be applicable to broadband CARS experiments to directly exploit electronic resonance effects for the purpose of single-shot concentration measurements of minority species. To quantify the enhancement in O2 sensitivity, comparative measurements at both a 266 and a 532 nm narrowband pump laser wavelength are presented, employing a 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyram (DCM) dye laser as a broadband laser source at 635 nm. An increase of approximately 13% in the ratio of the rotational CARS cross sections of O2 and N2 was obtained. The broad spectral width of the CARS excitation profile was approximately equal for both setups. Further enhancement should be achievable by shifting the narrowband pump laser closer toward 176 nm, for example, with a frequency-doubled optical parametric oscillator or an excimer laser. The principal concept of this experiment should also be applicable to broadband CARS experiments to directly exploit electronic resonance effects of the narrowband pump laser with electronic transitions of minority species for the purpose of single-shot concentration measurements of those species.

Schenk, Martin; Seeger, Thomas; Leipertz, Alfred

2005-07-01T23:59:59.000Z

487

Finite temperature effects on the X-ray absorption spectra of lithium compounds: First-principles interpretation of X-ray Raman measurements  

SciTech Connect (OSTI)

We elucidate the role of room-temperature-induced instantaneous structural distortions in the Li K-edge X-ray absorption spectra (XAS) of crystalline LiF, Li{sub 2}SO{sub 4}, Li{sub 2}O, Li{sub 3}N, and Li{sub 2}CO{sub 3} using high resolution X-ray Raman spectroscopy (XRS) measurements and first-principles density functional theory calculations within the eXcited electron and Core Hole approach. Based on thermodynamic sampling via ab initio molecular dynamics simulations, we find calculated XAS in much better agreement with experiment than those computed using the rigid crystal structure alone. We show that local instantaneous distortion of the atomic lattice perturbs the symmetry of the Li 1s core-excited-state electronic structure, broadening spectral line-shapes and, in some cases, producing additional spectral features. The excellent agreement with high-resolution XRS measurements validates the accuracy of our first-principles approach to simulating XAS, and provides both accurate benchmarks for model compounds and a predictive theoretical capability for identification and characterization of multi-component systems, such as lithium-ion batteries, under working conditions.

Pascal, Tod A.; Prendergast, David, E-mail: dgprendergast@lbl.gov [The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, California 94720 (United States)] [The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, California 94720 (United States); Boesenberg, Ulrike; Kostecki, Robert; Richardson, Thomas J. [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States)] [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States); Weng, Tsu-Chien; Sokaras, Dimosthenis; Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford, California 94720 (United States)] [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford, California 94720 (United States); McDermott, Eamon; Moewes, Alexander [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, Saskatchewan S7N 5E2 (Canada)] [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, Saskatchewan S7N 5E2 (Canada); Cabana, Jordi [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States) [Environmental Energy Technologies Division, LBNL, Berkeley, California 94720 (United States); Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60605 (United States)

2014-01-21T23:59:59.000Z

488

Organic Cyclic Difluoramino-Nitramines: Infrared and Raman Spectroscopy of 3,3,7,7-tetrakis(difluoramino)octahydro 1,5-dinitro-1,5-diazocine (HNFX)  

SciTech Connect (OSTI)

We present the first vibrational structure investigation of 3,3,7,7-tetrakis(difluoramino)octahydro-1,5-dinitro- 1,5-diazocine (HNFX) - and, more generally, of a member of the new class of gem-bis(difluoramino)-substituted heterocyclic nitramine energetic materials - using combined theoretical and experimental approaches. Optimized molecular structure and vibrational spectra of the Ci... symmetry conformer constituting the HNFX crystal were computed using density functional theory methods. Fourier transform infrared and Raman spectra of HNFX crystalline samples were also collected at ambient temperature and pressure. The average deviation of calculated structural parameters from X-ray diffraction data is {approx}1% at the B3LYP/6-311 + + G(d,p) level of theory, suggesting the absence of significant molecular distortion induced by the crystal field. Very good agreement was found between simulated and measured spectra, allowing reliable assignment of the fundamental normal modes of vibration of the HNFX crystal. Detailed analysis of the normal modes of the C-(NF{sub 2}){sub 2} and N-NO{sub 2} moieties was performed due to their critical importance in the initial steps of the molecular homolytic fragmentation process.

Weck, P.; Gobin, C; Kim, E; Pravica, M

2009-01-01T23:59:59.000Z

489

Raman E{sub 1} and E{sub 1} + {delta}{sub 1} resonances in a system of unstrained germanium quantum dots  

SciTech Connect (OSTI)

The positions and shapes of the Raman E{sub 1} and E{sub 1} + {delta}{sub 1} resonances of optical phonons are studied as functions of the size of unstrained germanium quantum dots. The quantum dots are grown by molecular-beam epitaxy in GaAs/ZnSe/Ge/ZnSe structures on GaAs(111) wafers. The positions of the E{sub 1} and E{sub 1} + {delta}{sub 1} resonances are found to shift by at most 0.3 eV. This shift is shown to be well described in terms of a cylindrical model using the quantization of the spectrum of bulk electron-hole states in germanium that form an exciton in a two-dimensional critical point. The fact that the peaks of the E{sub 1} and E{sub 1} + {delta}{sub 1} resonances appear separately has been detected for the first time, and it is related to the transformation of the interband density of states into a delta function because of spectrum quantization. An increase in the resonance amplitudes in quantum dots as compared to the bulk case is related to the degeneracy multiplicity of the exciton state in the (111) direction.

Talochkin, A. B., E-mail: tal@thermo.isp.nsc.ru; Teys, S. A.; Suprun, S. P. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Division (Russian Federation)

2006-05-15T23:59:59.000Z

490

A general time-dependent route to Resonance-Raman spectroscopy including Franck-Condon, Herzberg-Teller and Duschinsky effects  

SciTech Connect (OSTI)

We present a new formulation of the time-dependent theory of Resonance-Raman spectroscopy (TD-RR). Particular attention has been devoted to the generality of the framework and to the possibility of including different effects (Duschinsky mixing, Herzberg-Teller contributions). Furthermore, the effects of different harmonic models for the intermediate electronic state are also investigated. Thanks to the implementation of the TD-RR procedure within a general-purpose quantum-chemistry program, both solvation and leading anharmonicity effects have been included in an effective way. The reliability and stability of our TD-RR implementation are validated against our previously proposed and well-tested time-independent procedure. Practical applications are illustrated with some closed- and open-shell medium-size molecules (anthracene, phenoxyl radical, benzyl radical) and the simulated spectra are compared to the experimental results. More complex and larger systems, not limited to organic compounds, can be also studied, as shown for the case of Tris(bipyridine)ruthenium(II) chloride.

Baiardi, Alberto; Barone, Vincenzo [Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126 Pisa (Italy); Bloino, Julien [Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126 Pisa (Italy); Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), UOS di Pisa, Area della Ricerca CNR, Via G. Moruzzi 1, I-56124 Pisa (Italy)

2014-09-21T23:59:59.000Z

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