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Sample records for rayleigh light scattering

  1. POLARIZED LIGHT REFLECTED AND TRANSMITTED BY THICK RAYLEIGH SCATTERING ATMOSPHERES

    SciTech Connect

    Natraj, Vijay; Hovenier, J. W.

    2012-03-20

    Accurate values for the intensity and polarization of light reflected and transmitted by optically thick Rayleigh scattering atmospheres with a Lambert surface underneath are presented. A recently reported new method for solving integral equations describing Chandrasekhar's X- and Y-functions is used. The results have been validated using various tests and techniques, including the doubling-adding method, and are accurate to within one unit in the eighth decimal place. Tables are stored electronically and expected to be useful as benchmark results for the (exo)planetary science and astrophysics communities. Asymptotic expressions to obtain Stokes parameters for a thick layer from those of a semi-infinite atmosphere are also provided.

  2. Multi-Point Interferometric Rayleigh Scattering using Dual-Pass Light Recirculation

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Cutler, Andrew D.

    2008-01-01

    This paper describes for the first time an interferometric Rayleigh scattering system using dual-pass light recirculation (IRS-LR) capable of simultaneously measuring at multiple points two orthogonal components of flow velocity in combustion flows using single shot laser probing. An additional optical path containing the interferometer input mirror, a quarter-wave plate, a polarization dependent beam combiner, and a high reflectivity mirror partially recirculates the light that is rejected by the interferometer. Temporally- and spatially-resolved acquisitions of Rayleigh spectra in a large-scale combustion-heated supersonic axi-symmetric jet were performed to demonstrate the technique. Recirculating of Rayleigh scattered light increases the number of photons analyzed by the system up to a factor of 1.8 compared with previous configurations. This is equivalent to performing measurements with less laser energy or performing measurements with the previous system in gas flows at higher temperatures.

  3. Ribosome formation from subunits studied by stopped-flow and Rayleigh light scattering.

    PubMed

    Antoun, Ayman; Pavlov, Michael Y.; Tenson, Tanel; Ehrenberg M, M åNs

    2004-01-01

    Light scattering and standard stopped-flow techniques were used to monitor rapid association of ribosomal subunits during initiation of eubacterial protein synthesis. The effects of the initiation factors IF1, IF2, IF3 and buffer conditions on subunit association were studied along with the role of GTP in this process. The part of light scattering theory that is essential for kinetic measurements is high-lighted in the main text and a more general treatment of Rayleigh scattering from macromolecules is given in an appendix. PMID:15103398

  4. Interferometric Rayleigh Scattering Measurement System

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel (Inventor); Danehy, Paul M. (Inventor); Lee, Joseph W. (Inventor)

    2008-01-01

    A method and apparatus for performing simultaneous multi-point measurements of multiple velocity components in a gas flow is described. Pulses of laser light are directed to a measurement region of unseeded gas to produce Rayleigh or Mie scattered light in a plurality of directions. The Rayleigh or Mie scattered light is collected from multiple directions and combined in a single collimated light beam. The Rayleigh or Mie scattered light is then mixed together with a reference laser light before it is passed through a single planar Fabry-Perot interferometer for spectral analysis. At the output of the interferometer, a high-sensitivity CCD camera images the interference fringe pattern. This pattern contains the spectral and spatial information from both the Rayleigh scattered light and the reference laser light. Interferogram processing software extracts and analyzes spectral profiles to determine the velocity components of the gas flow at multiple points in the measurement region. The Rayleigh light rejected by the interferometer is recirculated to increase the accuracy and the applicability of the method for measurements at high temperatures without requiring an increase in the laser energy.

  5. Rapid determination of ciprofloxacin lactate in drugs by the Rayleigh light scattering technique

    NASA Astrophysics Data System (ADS)

    Xiao, Jian Bo; Yang, Chun Sheng; Lian Ren, Fen; Jiang, Xin Yu; Xu, Ming

    2007-03-01

    A Rayleigh light scattering technique to determine ciprofloxacin lactate (CPFL) in drugs by tetraphenylboron sodium (TPB) was developed. Ciprofloxacin lactate was found to bind B(C6H5)4- anion and transformed to CPFL-TPB aggregate which displayed intense Rayleigh scattering light. Effects of factors such as wavelength, acidity, stabilizers and interferents on the RLS of CPFL-TPB were investigated in detail. The RLS intensity of the CPFL-TPB suspension was obtained in acetate buffer (0.50 mol L-1, pH = 4.0). The Rayleigh scattering light intensity at the maximum RLS peak of 408 nm was linear to the concentration of ciprofloxacin lactate in the range of 8.0-20.0 µg mL-1 with a detection limit of 6.0 µg mL-1. Good results were also obtained with the recovery range of 93.68-104.06%. The method was applied to determine ciprofloxacin lactate in injections, eye drops and tablets, showing high sensitivity and accuracy compared with the high performance liquid chromatography method (HPLC) according to Chinese Pharmacopoeia.

  6. Rayleigh Scattering Diagnostics Workshop

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard (Compiler)

    1996-01-01

    The Rayleigh Scattering Diagnostics Workshop was held July 25-26, 1995 at the NASA Lewis Research Center in Cleveland, Ohio. The purpose of the workshop was to foster timely exchange of information and expertise acquired by researchers and users of laser based Rayleigh scattering diagnostics for aerospace flow facilities and other applications. This Conference Publication includes the 12 technical presentations and transcriptions of the two panel discussions. The first panel was made up of 'users' of optical diagnostics, mainly in aerospace test facilities, and its purpose was to assess areas of potential applications of Rayleigh scattering diagnostics. The second panel was made up of active researchers in Rayleigh scattering diagnostics, and its purpose was to discuss the direction of future work.

  7. Development of a noninvasive diabetes screening device using the ratio of fluorescence to Rayleigh scattered light

    NASA Astrophysics Data System (ADS)

    Yu, Nai-Teng; Krantz, Brian S.; Eppstein, Jonathan A.; Ignotz, Keith D.; Samuels, Mark A.; Long, James R.; Price, John

    1996-07-01

    We have developed a new lens measurement system that simultaneously measures the intensities of fluorescence and Rayleigh components at various distances into the lens along the optical axis. The noninvasive measurement is performed through an undilated pupil, and with the assistance of a pupil tracking system that facilitates maintaining the x and y positions of the sample volume to within +/- 100 micrometers of any programmed 'lock' position. The intensity of the Rayleigh component that is used to normalize the measured fluorescent signal serves to correct the attenuation effects due to absorption and lens light scatter. This report, resulting from a SpectRx Site L clinical study using a refined instrumentation, presents analysis of fluorescence and Rayleigh data from the lenses of 923 controls and 239 diabetic subjects ranging from 23 to 75 years old. Fluorescence and Rayleigh data have been obtained via confocal mode from various locations nominally along the lens optical axis for controls and diabetics, at different ages, using three pairs of excitation and collection wavelengths: 364/495 nm, 434/495 nm, and 485/515 nm. For control subjects, there exists a strong, almost linear relationship between age and fluorescence, while diabetic subjects tend to deviate from this age-fluorescence relationship. Our data show that the lenses of diabetic patients are subject to an accelerated aging process, presumably due to an elevated level of brown and fluorescence protein adducts and crosslinks from nonenzymatic glycosylation. We have also shown that by using the measured Rayleigh profiles to normalize the measured fluorescence, most of the absorption effects are removed and therefore the separation between the fluorescence of diabetics and controls is greatly improved. Thus, the device for measuring fluorescence/Rayleigh ratios can be used to noninvasively screen populations for possible undiagnosed diabetes.

  8. Rayleigh's Scattering Revised

    NASA Astrophysics Data System (ADS)

    Kolomiets, Sergey; Gorelik, Andrey

    Mie’s waves while sounding within coincident volumes. Being sensitive to the size of scatters, Mie’s waves can give us additional information about particle size distribution. But how about using several wavelengths corresponding to Rayleigh’s diffraction on scatters only? Can any effects be detected in such a case and what performance characteristics of the equipment are required to detect them? The deceptive simplicity of the negative answer to the first part of the question posed will disappear if one collects different definitions of Rayleigh's scattering and consider them more closely than usually. Several definitions borrowed from the introductory texts and most popular textbooks and articles can be seen as one of the reasons for the research presented in the report. Hopefully, based on the comparison of them all, anyone could easily conclude that Rayleigh's scattering has been analyzed extensively, but despite this extensive analysis made fundamental ambiguities in introductory texts are not eliminated completely to date. Moreover, there may be found unreasonably many examples on how these ambiguities have already caused an error to be foreseen, published on the one article, amplified in another one, then cited with approval in the third one, before being finally corrected. Everything indicated that in the light of all the lesions learned and based on modern experimental data, it is time to address these issues again. After the discussion of ambiguities of Rayleigh's scattering concepts, the development of the corrections to original ideas looks relatively easy. In particular, there may be distinguished at least three characteristic regions of the revised models application from the point of view of the scattered field statistical averaging. The authors of the report suggest naming them Rayleigh’s region, Einstein’s region and the region with compensations of the scattering intensity. The most important fact is that the limits of applicability of all

  9. Spontaneous Rayleigh-Brillouin scattering of ultraviolet light in nitrogen, dry air, and moist air.

    PubMed

    Witschas, Benjamin; Vieitez, Maria O; van Duijn, Eric-Jan; Reitebuch, Oliver; van de Water, Willem; Ubachs, Wim

    2010-08-01

    Atmospheric lidar techniques for the measurement of wind, temperature, and optical properties of aerosols rely on the exact knowledge of the spectral line shape of the scattered laser light on molecules. We report on spontaneous Rayleigh-Brillouin scattering measurements in the ultraviolet at a scattering angle of 90 degrees on N(2) and on dry and moist air. The measured line shapes are compared to the Tenti S6 model, which is shown to describe the scattering line shapes in air at atmospheric pressures with small but significant deviations. We demonstrate that the line profiles of N(2) and air under equal pressure and temperature conditions differ significantly, and that this difference can be described by the S6 model. Moreover, we show that even a high water vapor content in air up to a volume fraction of 3.6vol.% has no influence on the line shape of the scattered light. The results are of relevance for the future spaceborne lidars on ADM-Aeolus (Atmospheric Dynamics Mission) and EarthCARE (Earth Clouds, Aerosols, and Radiation Explorer). PMID:20676176

  10. Spontaneous Rayleigh-Brillouin scattering of ultraviolet light in nitrogen, dry air, and moist air.

    PubMed

    Witschas, Benjamin; Vieitez, Maria O; van Duijn, Eric-Jan; Reitebuch, Oliver; van de Water, Willem; Ubachs, Wim

    2010-08-01

    Atmospheric lidar techniques for the measurement of wind, temperature, and optical properties of aerosols rely on the exact knowledge of the spectral line shape of the scattered laser light on molecules. We report on spontaneous Rayleigh-Brillouin scattering measurements in the ultraviolet at a scattering angle of 90 degrees on N(2) and on dry and moist air. The measured line shapes are compared to the Tenti S6 model, which is shown to describe the scattering line shapes in air at atmospheric pressures with small but significant deviations. We demonstrate that the line profiles of N(2) and air under equal pressure and temperature conditions differ significantly, and that this difference can be described by the S6 model. Moreover, we show that even a high water vapor content in air up to a volume fraction of 3.6vol.% has no influence on the line shape of the scattered light. The results are of relevance for the future spaceborne lidars on ADM-Aeolus (Atmospheric Dynamics Mission) and EarthCARE (Earth Clouds, Aerosols, and Radiation Explorer).

  11. Using gold nanoparticles as probe for detection of salmeterol xinafoate by resonance Rayleigh light scattering.

    PubMed

    Bi, Shuyun; Wang, Tianjiao; Wang, Yu; Zhao, Tingting; Zhou, Huifeng

    2015-01-25

    The paper explores the method of determination of salmeterol xinafoate at nanogram level with gold nanoparticles (AuNPs) probe, to measure the intensity of resonance Rayleigh light scattering (RLS) by a common spectrofluorometer. The RLS intensity of salmeterol xinafoate was greatly enhanced by AuNPs, with the maximum scattering peak at 357 nm. The salmeterol xinafoate was determined basing on the binding of salmeterol xinafoate to AuNPs by electrostatic adsorption. Under the optimum conditions, the enhanced RLS intensity was directly proportional to the concentration of salmeterol xinafoate in the range of 0.054-6.038 μg mL(-1) with a good linear relationship (r=0.9928). The limit of detection (LOD) was 9.48 ng mL(-1). The interference tests were performed carefully. With the proposed method, the synthetic samples were analyzed satisfactorily, the recovery and RSD were 102.5-103.0% and 0.67-1.0% respectively. PMID:25173524

  12. Improvement in Rayleigh Scattering Measurement Accuracy

    NASA Technical Reports Server (NTRS)

    Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.

    2012-01-01

    Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous velocity, density, and temperature measurements. The Fabry-Perot interferometer or etalon is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating these flow properties. This paper investigates the use of an acousto-optic frequency shifting device to improve measurement accuracy in Rayleigh scattering experiments at the NASA Glenn Research Center. The frequency shifting device is used as a means of shifting the incident or reference laser frequency by 1100 MHz to avoid overlap of the Rayleigh and reference signal peaks in the interference pattern used to obtain the velocity, density, and temperature measurements, and also to calibrate the free spectral range of the Fabry-Perot etalon. The measurement accuracy improvement is evaluated by comparison of Rayleigh scattering measurements acquired with and without shifting of the reference signal frequency in a 10 mm diameter subsonic nozzle flow.

  13. Amplification of resonant Rayleigh light scattering response using immunogold colloids for detection of lysozyme.

    PubMed

    Truong, Phuoc Long; Choi, Seung Phill; Sim, Sang Jun

    2013-10-25

    A strategy for attomolar-level detection of small molecule-size proteins is reported based on Rayleigh light scattering spectroscopy of individual nanoplasmonic aptasensors by exploiting the outstanding characteristics of gold colloids to amplify the nontransparent resonant signal at ultralow analyte concentrations. The fabrication method utilizes thiol-mediated adsorption of a DNA aptamer on the immobilized Au nanoparticle surface, the interfacial binding characteristics of the aptamer with its target molecules, and the antibody-antigen interaction through plasmonic resonance coupling of the Au nanoparticles. Using lysozyme as a model analyte for disease detection, the detection limit of the aptasensor is ∼7 × 10(3) aM, corresponding to the LSPR λmax shift of ∼2.25 nm. Up to a 380% increase in the localized resonant λmax shift is demonstrated upon antibody binding to the analyte compared to the primary response during signal amplification using immunogold colloids. This enhancement leads to a limit of detection of ∼7 aM, which is an improvement of three orders of magnitude. The results demonstrate substantial promise for developing coupled plasmonic nanostructures for ultrasensitive detection of various biological and chemical analytes.

  14. Rayleigh light scattering detection of three α1-adrenoceptor antagonists coupled with high performance liquid chromatograph

    NASA Astrophysics Data System (ADS)

    Li, Ai Ping; Peng, Huanjun; Peng, Jing Dong; Zhou, Ming Qiong; Zhang, Jing

    2015-08-01

    Herein, a Rayleigh light-scattering (RLS) detection method combined with high performance liquid chromatograph (HPLC) without any post-column probe was developed for the separation and determination of three α1-adrenoceptor antagonists. The quantitative analysis is benefiting from RLS signal enhancement upon addition of methanol which induced molecular aggregation to form an hydrophobic interface between aggregates and water that produce a sort of superficial enhanced scattering effect. A good chromatographic separation among the compounds was achieved using a Gemini 5u C18 reversed phase column (250 mm × 4.6 mm; 4 μm) with a mobile phase consisting of methanol and ammonium acetate-formic acid buffer solution (25 mM; pH = 3.0) at the flow rate of 0.7 mL min-1. The RLS signal was monitored at λex = λem = 354 nm. A limit of detection (LOD) of 0.065-0.70 μg L-1 was reached and a linear range was found between peak height and concentration in the range of 0.75-15 μg L-1 for doxazosin mesylate (DOX), 0.075-3.0 μg L-1 for prazosin hydrochloride (PRH), and 0.25-5 μg L-1 for terazosin hydrochloride (TEH), with linear regression coefficients all above 0.999. Recoveries from spiked urine samples were 88.4-99.0% which is within acceptable limits. The proposed method is convenient, reliable and sensitive which has been used successfully in human urine samples.

  15. Improvement in Suppression of Pulsed Nd:YAG Laser Light With Iodine Absorption Cells for Filtered Rayleigh Scattering Measurements

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Buggele, Alvin E

    1997-01-01

    Filtered Rayleigh scattering using iodine absorption cells is an effective technique for obtaining density, temperature, and velocity measurements in high speed confined flows. By tuning a single frequency laser to a strong iodine absorption line, stray scattered laser light can be greatly suppressed. For example, the minimum transmission predicted by an iodine absorption model calculation is less than 10(exp -5) at the 18788.44/cm line using a 200 mm absorption cell containing iodine vapor at 0.46 T. Measurements obtained by other researches using a CW Nd:YAG laser agree with the model calculations. However, measurements made by us and by others using Q-switched, injection-seeded, frequency doubled Nd:YAG lasers only show minimum transmission of about 3 x 10(exp -3). This greatly reduces the applicability of the filtered Rayleigh scattering technique using these lasers in experiments having large amounts of stray scattered laser light. The purposes of the present study are to characterize the spectrum of the excess light transmitted by the iodine cell and to make changes to the laser to reduce the transmitted laser light. Transmission data as a function of laser frequency for the iodine absorption line at 18788.44/cm are presented. A planar mirror Fabry-Perot interferometer was used to characterize the frequency spectrum of the light passed through the cell. Measurements taken with the laser tuned to the center of the iodine absorption line show the light transmitted through the iodine cell to have a component with a bandwidth of about 40 GHz. This is probably caused by other modes in the laser that exist in spite of the single frequency injection beam. A second broadband component was also observed, possibly caused by the laser flash lamps or by fluorescence. An intracavity etalon was installed in the laser oscillator cavity to suppress the 40 GHz component. Measurements taken with the etalon tuned to the injection frequency showed a reduction in the transmitted

  16. Rayleigh scattering of linear alkylbenzene in large liquid scintillator detectors

    SciTech Connect

    Zhou, Xiang Zhang, Zhenyu; Liu, Qian; Zheng, Yangheng; Wurm, Michael; Zhang, Qingmin; Ding, Yayun; Zhou, Li; Cao, Jun; Wang, Yifang

    2015-07-15

    Rayleigh scattering poses an intrinsic limit for the transparency of organic liquid scintillators. This work focuses on the Rayleigh scattering length of linear alkylbenzene (LAB), which will be used as the solvent of the liquid scintillator in the central detector of the Jiangmen Underground Neutrino Observatory. We investigate the anisotropy of the Rayleigh scattering in LAB, showing that the resulting Rayleigh scattering length will be significantly shorter than reported before. Given the same overall light attenuation, this will result in a more efficient transmission of photons through the scintillator, increasing the amount of light collected by the photosensors and thereby the energy resolution of the detector.

  17. Blue Skies, Coffee Creamer, and Rayleigh Scattering

    ERIC Educational Resources Information Center

    Liebl, Michael

    2010-01-01

    The first physical explanation of Earths blue sky was fashioned in 1871 by Lord Rayleigh. Many discussions of Rayleigh scattering and approaches to studying it both in and out of the classroom are available. Rayleigh scattering accounts for the blue color of the sky and the orange/red color of the Sun near sunset and sunrise, and a number of…

  18. Mie and Rayleigh modeling of visible-light scattering in neonatal skin

    NASA Astrophysics Data System (ADS)

    Saidi, Iyad S.; Jacques, Steven L.; Tittel, Frank K.

    1995-11-01

    Reduced-scattering coefficients of neonatal skin were deduced in the 450-750-nm range from integrating-sphere measurements of the total reflection and total transmission of 22 skin samples. The reduced-scattering coefficients increased linearly at each wavelength with gestational maturity. The distribution of diameters d and concentration rho A of the skin-sample collagen fibers were measured in histological sections of nine neonatal skin samples of varying gestational ages. An algorithm that calculates Mie scattering by cylinders was used to model the scattering by the collagen fibers in the skin. The fraction of the reduced-scattering coefficient mu s` that was attributable to Mie scattering by

  19. Cell Thickness Effects in the Determination of Elastic Constant Ratios by Observing Rayleigh Light Scattered Intensity

    NASA Astrophysics Data System (ADS)

    Hall, Richard; Miyachi, Kouichi; Newton, David; Takezoe, Hideo; Fukuda, Atsuo

    1992-02-01

    The effects of the finite scattering volume on the values of elastic constant ratios determined have been studied by computer simulation. The errors in the simulated values of K1/K2 and K3/K2 are dependent on the position of the starting angle of the scan. The error is greatest for thinner cells (≈7 μm) and in the angular regions where the geometrical factor Gm introduced by de Gennes, or a component of the scattering vector q becomes zero, i.e. for external scattering angles approximately less than 10° and those between approximately 20° and 60°, depending on the scattering geometry used. The approximation introduced by van der Meulen and Zijlstra in defining the orthogonal base system (\\hat{\\mbi{e}}1, \\hat{\\mbi{e}}2, \\hat{\\mbi{e}}3) has also been discussed; it is inappropriate in thin cells to use the scattering vector q instead of the wave vector \\mbi{k}l of the director fluctuations when determining K1/K2.

  20. Rayleigh light scattering study on the supramolecular interactions of beta-cyclodextrin derivatives with tetrakis(4-methoxylphenyl)porphyrin.

    PubMed

    Yang, Ronghua; Li, Ke'an; Wang, Kemin; Liu, Feng; Li, Na; Zhao, Fenglin

    2003-01-01

    The supramolecular interactions of beta-cyclodextrin(beta-CD) and four kinds of alkylated beta-cyclodextrin (beta-CDs), i.e. heptakis (2,6-di-O-isobutyl)-beta-cyclodextrin (Ob-beta-CD), heptakis (2,6-di-O-n-octyl)-beta-cyclodextrin (Oc-beta-CD), heptakis (2,6-di-O-n-dodecyl)-beta-cyclodextrin (Od-beta-CD) and heptakis (2,6-di-O-n-hexadecyl)-beta-cyclodextrin (Oh-beta-CD) with tetrakis(4-methoxylphenyl)porphyrin (TMOPP) have been investigated by Rayleigh light scattering (RLS) technique. Beta-CDs form 2:1 inclusion complex with TMOPP following an obvious RLS enhancement of TMOPP. The inclusion abilities of different beta-CDs were compared. The results show that the inclusion ability of beta-CDs is related to the size of the alkylated substituent. Thus, a new mechanism of inclusion interaction has been proposed. The exact stoichiometric ratios and the association constants of the inclusion complexes have been examined by application of curve fitting method.

  1. Collision-induced hyper-Rayleigh light scattering in gaseous dihydrogen-neon mixtures

    SciTech Connect

    Glaz, W.; Bancewicz, T.; Godet, J.-L.; Haskopoulos, A.; Maroulis, G.

    2011-07-15

    Cartesian components of the collision-induced (CI) hyperpolarizability {Delta}{beta} tensor are computed for the linear, T-shaped, and 45 deg. configurations of the H{sub 2}-Ne pair in the intermolecular range 3 to 14 bohr. Symmetry-adapted components {Delta}{beta}{sub {lambda}L}{sup (K)}(R) of the vector (K=1) part, as well as the septor (K=3) part, of the H{sub 2}-Ne CI hyperpolarizability are calculated starting from the ab initio Cartesian hyperpolarizability tensor values transformed into their spherical counterparts. By applying these quantities, the vector together with the septor collision-induced hyper-Rayleigh (CIHR) spectra for the H{sub 2}-Ne binary gas mixture are determined in the frequency range from -1250 to 2500 cm{sup -1}. The profiles are partially employed as a benchmarking device to estimate the importance of the short intermolecular distance part of the {Delta}{beta}(R) dependence. The depolarization ratio of the CIHR spectra in the whole frequency range is also calculated. The nature of the CIHR signal and the feasibility of the related experiments are discussed and analyzed.

  2. Rayleigh Scattering Diagnostic for Dynamic Measurement of Velocity and Temperature

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Panda, J.

    2001-01-01

    A new technique for measuring dynamic gas velocity and temperature is described. The technique is based on molecular Rayleigh scattering of laser light, so no seeding of the flow is necessary. The Rayleigh scattered light is filtered with a fixed cavity, planar mirror Fabry-Perot interferometer. A minimum number of photodetectors were used in order to allow the high data acquisition rate needed for dynamic measurements. One photomultiplier tube (PMT) was used to measure the total Rayleigh scattering, which is proportional to the gas density. Two additional PMTs were used to detect light that passes through two apertures in a mask located in the interferometer fringe plane. An uncertainty analysis was used to select the optimum aperture parameters and to predict the measurement uncertainty due to photon shot-noise. Results of an experiment to measure the velocity of a subsonic free jet are presented.

  3. Bacterial Light-Harvesting Complexes Showing Giant Second-Order Nonlinear Optical Response as Revealed by Hyper-Rayleigh Light Scattering.

    PubMed

    Ma, Fei; Yu, Long-Jiang; Ma, Xiao-Hua; Wang, Peng; Wang-Otomo, Zheng-Yu; Zhang, Jian-Ping

    2016-09-01

    The second-order nonlinear optical (NLO) properties of light-harvesting complexes (LHs) from the purple photosynthetic bacteria Thermochromatium (Tch.) tepidum were investigated for the first time by means of hyper-Rayleigh scattering (HRS). The carotenoid (Car) molecules bound to the isolated LH1 and LH2 proteins gave rise to second-harmonic scattering; however, they showed an opposite effect of the collective contribution from Car, that is, the first hyperpolarizability (β) reduced substantially from (10 510 ± 370) × 10(-30) esu for LH1 to (360 ± 120) × 10(-30) esu for LH2. Chromatophores of Tch. tepidum also showed a giant hyperpolarizability of (11 640 ± 630) × 10(-30) esu. On the basis of the structural information on bacterial LHs, it is found that the effective β of an LH is governed by the microenvironment and orientational correlation among the Car chromophores, which is concluded to be coherently enhanced for LH1. For LH2, however, additional destructive effects between different Car molecules may account for the small β value. This work demonstrates that LH1 and native membranes of purple bacteria can be potent NLO materials and that HRS is a promising spectroscopic means for investigating structural information of pigment-protein supramolecules. PMID:27505442

  4. Multiple-Point Mass Flux Measurement System Using Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.; Clem, Michelle M.

    2009-01-01

    A multiple-point Rayleigh scattering diagnostic is being developed to provide mass flux measurements in gas flows. Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous density, temperature, and velocity measurements. Rayleigh scattered light from a focused 18 Watt continuous-wave laser beam is directly imaged through a solid Fabry-Perot etalon onto a CCD detector which permits spectral analysis of the light. The spatial resolution of the measurements is governed by the locations of interference fringes, which can be changed by altering the etalon characteristics. A prototype system has been used to acquire data in a Mach 0.56 flow to demonstrate feasibility of using this system to provide mass flux measurements. Estimates of measurement uncertainty and recommendations for system improvements are presented

  5. Progress on a Rayleigh Scattering Mass Flux Measurement Technique

    NASA Technical Reports Server (NTRS)

    Mielke-Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.; Hirt, Stefanie M.

    2010-01-01

    A Rayleigh scattering diagnostic has been developed to provide mass flux measurements in wind tunnel flows. Spectroscopic molecular Rayleigh scattering is an established flow diagnostic tool that has the ability to provide simultaneous density and velocity measurements in gaseous flows. Rayleigh scattered light from a focused 10 Watt continuous-wave laser beam is collected and fiber-optically transmitted to a solid Fabry-Perot etalon for spectral analysis. The circular interference pattern that contains the spectral information that is needed to determine the flow properties is imaged onto a CCD detector. Baseline measurements of density and velocity in the test section of the 15 cm x 15 cm Supersonic Wind Tunnel at NASA Glenn Research Center are presented as well as velocity measurements within a supersonic combustion ramjet engine isolator model installed in the tunnel test section.

  6. Rayleigh scattering measurements of several fluorocarbon gases.

    PubMed

    Zadoo, Serena; Thompson, Jonathan E

    2011-11-01

    Integrating nephelometers are commonly used to monitor airborne particulate matter. However, they must be calibrated prior to use. The Rayleigh scattering coefficients (b(RS), Mm(-1)), scattering cross sections (σ(RS), cm(2)), and Rayleigh multipliers for tetrafluoromethane (R-14), sulfur hexafluoride, pentafluoroethane (HFC-125), hexafluoropropene (HFC-216), 1,1,1,2,3,3,3,-heptafluoropropane (HFC-227ea), and octafluorocyclobutane (C-318) are reported from measurements made using a Radiance Research M903 integrating nephelometer operating at λ = 530 nm and calibration with gases of known scattering constants. Rayleigh multipliers (±90% conf. int.) were found to be 2.6 ± 0.5, 6.60 ± 0.07, 7.5 ± 1, 14.8 ± 0.9, 15.6 ± 0.5, and 22.3 ± 0.8 times that of air, respectively. To the best of our knowledge, these are the first reported values for R-14, HFC-216, HFC-125, and C-318. Experimental accuracy is supported through measurements of values for SF(6) and HFC-227ea which agree to within 3% of previous literature reports. In addition to documenting fundamental Rayleigh scattering data for the first time, the information presented within will find use for calibration of optical scattering sensors such as integrating nephelometers. PMID:22027960

  7. Rayleigh-Brillouin Scattering in Binary-Gas Mixtures.

    PubMed

    Gu, Z; Ubachs, W; Marques, W; van de Water, W

    2015-06-19

    Precise measurements are performed on spectral line shapes of spontaneous Rayleigh-Brillouin scattering in mixtures of the noble gases Ar and Kr, with He. Admixture of a light He atomic fraction results in marked changes of the spectra, although in all experiments He is merely a spectator atom: it affects the relaxation of density fluctuations of the heavy constituent, but its contribution to the scattered light intensity is negligibly small. The results are compared to a theory for the spectral line shape without adjustable parameters, yielding excellent agreement for the case of binary monatomic gases, signifying a step towards modeling and understanding of light scattering in more complex molecular media. PMID:26196978

  8. Transient Rayleigh scattering from single semiconductor nanowires

    SciTech Connect

    Montazeri, Mohammad; Jackson, Howard E.; Smith, Leigh M.; Yarrison-Rice, Jan M.; Kang, Jung-Hyun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati

    2013-12-04

    Transient Rayleigh scattering spectroscopy is a new pump-probe technique to study the dynamics and cooling of photo-excited carriers in single semiconductor nanowires. By studying the evolution of the transient Rayleigh spectrum in time after excitation, one can measure the time evolution of the density and temperature of photo-excited electron-hole plasma (EHP) as they equilibrate with lattice. This provides detailed information of dynamics and cooling of carriers including linear and bimolecular recombination properties, carrier transport characteristics, and the energy-loss rate of hot electron-hole plasma through the emission of LO and acoustic phonons.

  9. Rayleigh scattering on the cavitation region emerging in liquids.

    PubMed

    Shneider, M N; Pekker, M

    2016-03-15

    It is shown that the scattering of laser radiation off cavitation ruptures in fluids is similar to scattering by gas particles. When the characteristic dimensions of microscopic voids and bubbles are considerably smaller than the laser wavelength, the scattered light is in the Rayleigh regime, which allows for the detection of early stage cavitation. Simple estimates of the scattered radiation intensity and the dynamics of its changes in connection with the generation of cavitation in the test volume are obtained, allowing us to find the critical conditions for cavitation inception. PMID:26977641

  10. Hyper-Rayleigh scattering in centrosymmetric systems

    NASA Astrophysics Data System (ADS)

    Williams, Mathew D.; Ford, Jack S.; Andrews, David L.

    2015-09-01

    Hyper-Rayleigh scattering (HRS) is an incoherent mechanism for optical second harmonic generation. The frequency-doubled light that emerges from this mechanism is not emitted in a laser-like manner, in the forward direction; it is scattered in all directions. The underlying theory for this effect involves terms that are quadratic in the incident field and involves an even-order optical susceptibility (for a molecule, its associated hyperpolarizability). In consequence, HRS is often regarded as formally forbidden in centrosymmetric media. However, for the fundamental three-photon interaction, theory based on the standard electric dipole approximation, representable as E13, does not account for all experimental observations. The relevant results emerge upon extending the theory to include E12M1 and E12E2 contributions, incorporating one magnetic dipolar or electric quadrupolar interaction, respectively, to a consistent level of multipolar expansion. Both additional interactions require the deployment of higher orders in the multipole expansion, with the E12E2 interaction analogous in rank and parity to a four-wave susceptibility. To elicit the correct form of response from fluid or disordered media invites a tensor representation which does not oversimplify the molecular components, yet which can produce results to facilitate the interpretation of experimental observations. The detailed derivation in this work leads to results which are summarized for the following: perpendicular detection of polarization components both parallel and perpendicular to the pump radiation, leading to distinct polarization ratio results, as well as a reversal ratio for forward scattered circular polarizations. The results provide a route to handling data with direct physical interpretation, to enable the more sophisticated design of molecules with sought nonlinear optical properties.

  11. Hyper-Rayleigh scattering in centrosymmetric systems

    SciTech Connect

    Williams, Mathew D.; Ford, Jack S.; Andrews, David L.

    2015-09-28

    Hyper-Rayleigh scattering (HRS) is an incoherent mechanism for optical second harmonic generation. The frequency-doubled light that emerges from this mechanism is not emitted in a laser-like manner, in the forward direction; it is scattered in all directions. The underlying theory for this effect involves terms that are quadratic in the incident field and involves an even-order optical susceptibility (for a molecule, its associated hyperpolarizability). In consequence, HRS is often regarded as formally forbidden in centrosymmetric media. However, for the fundamental three-photon interaction, theory based on the standard electric dipole approximation, representable as E1{sup 3}, does not account for all experimental observations. The relevant results emerge upon extending the theory to include E1{sup 2}M1 and E1{sup 2}E2 contributions, incorporating one magnetic dipolar or electric quadrupolar interaction, respectively, to a consistent level of multipolar expansion. Both additional interactions require the deployment of higher orders in the multipole expansion, with the E1{sup 2}E2 interaction analogous in rank and parity to a four-wave susceptibility. To elicit the correct form of response from fluid or disordered media invites a tensor representation which does not oversimplify the molecular components, yet which can produce results to facilitate the interpretation of experimental observations. The detailed derivation in this work leads to results which are summarized for the following: perpendicular detection of polarization components both parallel and perpendicular to the pump radiation, leading to distinct polarization ratio results, as well as a reversal ratio for forward scattered circular polarizations. The results provide a route to handling data with direct physical interpretation, to enable the more sophisticated design of molecules with sought nonlinear optical properties.

  12. Simultaneous CARS and Interferometric Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Grinstead, Keith D., Jr.; Tedder, Sarah; Cutler, Andrew D.

    2006-01-01

    This paper reports for the first time the combination of a dual-pump coherent anti-Stokes Raman scattering system with an interferometric Rayleigh scattering system (CARS - IRS) to provide time-resolved simultaneous measurement of multiple properties in combustion flows. The system uses spectrally narrow green (seeded Nd:YAG at 532 nm) and yellow (552.9 nm) pump beams and a spectrally-broad red (607 nm) beam as the Stokes beam. A spectrometer and a planar Fabry-Perot interferometer used in the imaging mode are used to record the spectrally broad CARS spectra and the spontaneous Rayleigh scattering spectra, respectively. Time-resolved simultaneous measurement of temperature, absolute mole fractions of N2, O2, and H2, and two components of velocity in a Hencken burner flame were performed to demonstrate the technique.

  13. Time-Resolved Rayleigh Scattering Measurements in Hot Gas Flows

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.; Sung, Chih-Jen

    2008-01-01

    A molecular Rayleigh scattering technique is developed to measure time-resolved gas velocity, temperature, and density in unseeded gas flows at sampling rates up to 32 kHz. A high power continuous-wave laser beam is focused at a point in an air flow field and Rayleigh scattered light is collected and fiber-optically transmitted to the spectral analysis and detection equipment. The spectrum of the light, which contains information about the temperature and velocity of the flow, is analyzed using a Fabry-Perot interferometer. Photomultipler tubes operated in the photon counting mode allow high frequency sampling of the circular interference pattern to provide time-resolved flow property measurements. Mean and rms velocity and temperature fluctuation measurements in both an electrically-heated jet facility with a 10-mm diameter nozzle and also in a hydrogen-combustor heated jet facility with a 50.8-mm diameter nozzle at NASA Glenn Research Center are presented.

  14. Rayleigh Scattering Measurements Using a Tunable Liquid Crystal Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Mielke-Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.

    2010-01-01

    Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous density, velocity, and temperature measurements. The Fabry-Perot interferometer or etalon is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating these flow properties. This paper investigates the use of a tunable liquid crystal (LC) Fabry-Perot etalon in Rayleigh scattering experiments at NASA Glenn Research Center. The LC etalon provides a robust interferometry system that can be tuned rapidly by adjusting the voltage applied to the liquid crystal interface. Tuning the interferometer is often necessary to control the physical locations of the concentric interference fringes when Rayleigh light is imaged through the LC etalon. The LC etalon diagnostic system was tested in a 1-cm diameter nozzle flow in two different scattering configurations to evaluate its usefulness for Rayleigh measurements compared to a traditional non-tunable fused silica Fabry-Perot etalon.

  15. The resonance Rayleigh light scattering spectral investigation on the interaction of DNA with camellia sinensis in the presence of CPC and its analytical application.

    PubMed

    Bi, Shuyun; Wang, Tianjiao; Zhao, Tingting; Wang, Yu

    2014-06-01

    A novel method with high sensitivity was designed for the determination of trace nucleic acids by using cationic surfactant cetylpyridinium chloride (CPC) and camellia sinensis (CS) as resonance Rayleigh light scattering (RLS) probes. It was found DNA could combine with CS and CPC in Tris-HCl buffer (pH=7.4). Under optimum conditions, the RLS intensity of DNA can be enhanced by CPC-CS obviously at 294nm, and the enhanced RLS intensity was directly proportional to DNA concentration in the range from 0.024 to 3.48μgmL(-1) with a good linear relationship (r=0.9940). The limit of detection (LOD) was 1.49ngmL(-1) (S/N=3). In addition, the effects of some interferences including K(+), Na(+), Mg(2+), Zn(2+), Cu(2+), Ca(2+) and glucose on the determination were studied. The developed RLS assay was successfully applied to three synthetic samples to measure DNA, the recovery was 94.7-106.3% and RSD was 0.58-3.33%.

  16. The resonance Rayleigh light scattering spectral investigation on the interaction of DNA with camellia sinensis in the presence of CPC and its analytical application

    NASA Astrophysics Data System (ADS)

    Bi, Shuyun; Wang, Tianjiao; Zhao, Tingting; Wang, Yu

    2014-06-01

    A novel method with high sensitivity was designed for the determination of trace nucleic acids by using cationic surfactant cetylpyridinium chloride (CPC) and camellia sinensis (CS) as resonance Rayleigh light scattering (RLS) probes. It was found DNA could combine with CS and CPC in Tris-HCl buffer (pH = 7.4). Under optimum conditions, the RLS intensity of DNA can be enhanced by CPC-CS obviously at 294 nm, and the enhanced RLS intensity was directly proportional to DNA concentration in the range from 0.024 to 3.48 μg mL-1 with a good linear relationship (r = 0.9940). The limit of detection (LOD) was 1.49 ng mL-1 (S/N = 3). In addition, the effects of some interferences including K+, Na+, Mg2+, Zn2+, Cu2+, Ca2+ and glucose on the determination were studied. The developed RLS assay was successfully applied to three synthetic samples to measure DNA, the recovery was 94.7-106.3% and RSD was 0.58-3.33%.

  17. An investigation on the interaction of DNA with hesperetin/apigenin in the presence of CTAB by resonance Rayleigh light scattering technique and its analytical application

    NASA Astrophysics Data System (ADS)

    Bi, Shuyun; Wang, Yu; Pang, Bo; Yan, Lili; Wang, Tianjiao

    2012-05-01

    Two new systems for measuring DNA at nanogram levels by a resonance Rayleigh light scattering (RLS) technique with a common spectrofluorometer were proposed. In the presence of cetyltrimethylammonium bromide (CTAB), the interaction of DNA with hesperetin and apigenin (two effective components of Chinese herbal medicine) could enhance RLS signals with the maximum peak at 363 and 433 nm respectively. The enhanced intensity of RLS was directly proportional to the concentration of DNA in the range of 0.022-4.4 μg mL-1 for DNA-CTAB-hesperetin system and 0.013-4.4 μg mL-1 for DNA-CTAB-apigenin system. The detection limit was 2.34 ng mL-1 and 2.97 ng mL-1 respectively. Synthetic samples were measured satisfactorily. The recovery of DNA-CTAB-hesperetin system was 97.3-101.9% and that of DNA-CTAB-apigenin system was 101.2-109.5%.

  18. Optical switching by stimulated thermal Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Peterson, Lauren M.

    1986-06-01

    Preliminary experiments were conducted whose ultimate goal is to develop all-optical control functions useful in an all-optical or optical-electronic hybrid digital computer or for optical interconnects. Stimulated thermal Rayleigh scattering (STRS) based upon generator experiments was pursued for scattering angles of 90 deg and 180 deg (backscattering). A pulsed nitrogen laser pumped dye laser served as the radiation source and the interaction medium was a liquid to which an absorbing dye was added. STRS amplifier experiments were successful and gain was observed and studied parametrically using eosine dye in ethanol. The gain was found to increase (although the gain coefficient decreased) with increasing pump power and the gain was found to be a maximum at an absorption coefficient of about 2.6 per cm. The generator experiments did not lead to stimulated scattering due to the limited output power of the laser and its multi-longitudinal spectral mode content. These studies will be continued along with analytical modeling in order to characterize the interaction and to enable the optimization of the scattering process.

  19. Rayleigh Scattering for Measuring Flow in a Nozzle Testing Facility

    NASA Technical Reports Server (NTRS)

    Gomez, Carlos R.; Panda, Jayanta

    2006-01-01

    A molecular Rayleigh-scattering-based air-density measurement system was built in a large nozzle-and-engine-component test facility for surveying supersonic plumes from jet-engine exhaust. A molecular Rayleigh-scattering-based air-density measurement system was built in a large nozzle-and-enginecomponent test facility for surveying supersonic plumes from jet-engine exhaust

  20. Technical Report: Rayleigh Scattering Combustion Diagnostic

    SciTech Connect

    Adams, Wyatt; Hecht, Ethan

    2015-07-29

    A laser Rayleigh scattering (LRS) temperature diagnostic was developed over 8 weeks with the goal of studying oxy-combustion of pulverized coal char in high temperature reaction environments with high concentrations of carbon dioxide. Algorithms were developed to analyze data collected from the optical diagnostic system and convert the information to temperature measurements. When completed, the diagnostic will allow for the kinetic gasification rates of the oxy-combustion reaction to be obtained, which was previously not possible since the high concentrations of high temperature CO2 consumed thermocouples that were used to measure flame temperatures inside the flow reactor where the combustion and gasification reactions occur. These kinetic rates are important for studying oxycombustion processes suitable for application as sustainable energy solutions.

  1. Ultraviolet Molecular Rayleigh Scattering Used to Measure Velocity in High-Speed Flow

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.

    1997-01-01

    Molecular Rayleigh scattering offers a means to measure gas flow parameters including density, temperature, and velocity. No seeding of the flow is necessary. The Rayleigh scattered power is proportional to the gas density, the spectral width is related to the gas temperature, and the shift in the frequency of the spectral peak is proportional to one component of the fluid velocity. Velocity measurements based on Rayleigh scattering are more suitable for high-speed flow, where the bulk fluid velocity is on the order of, or larger than, the molecular thermal velocities. Use of ultraviolet wavelengths for Rayleigh scattering diagnostics is attractive for two reasons. First, the Rayleigh scattering cross section is proportional to the inverse 4th power of the wavelength. And second, the reflectivity of metallic surfaces is generally less than it is at longer wavelengths. This is of particular interest in confined flow situations, such as in small wind tunnels and aircraft engine components, where the stray laser light scattered from the windows and internal surfaces in the test facility limits the application of Rayleigh scattering diagnostics. In this work at the NASA Lewis Research Center, molecular Rayleigh scattering of the 266-nm fourth harmonic of a pulsed, injection seeded Nd:YAG (neodymium:yttriumaluminum- garnet) laser was used to measure velocity in a supersonic free air jet with a 9.3- mm exit diameter. The frequency of the Rayleigh scattered light was analyzed with a planar mirror Fabry-Perot interferometer used in a static imaging mode, with the images recorded on a cooled, high-quantum-efficiency charge-coupled discharge (CCD) camera. In addition, some unshifted light from the same laser pulse was imaged through the interferometer to generate a reference. Data were obtained with single laser pulses at velocities up to Mach 1.3. The measured velocities were in good agreement with velocities calculated from isentropic flow relations. Our conclusion from

  2. High-speed laser anemometry based on spectrally resolved Rayleigh scattering

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.

    1991-01-01

    Laser anemometry in unseeded flows based on the measurement of the spectrum of Rayleigh scattered laser light is reviewed. The use of molecular scattering avoids the well known problems (particle lag, biasing effects, seed generation, seed injection) of seeded flows. The fundamental limits on velocity measurement accuracy are determined using maximum likelihood methods. Measurement of the Rayleigh spectrum with scanning Fabry-Perot interferometers is analyzed and accuracy limits are established for both single pass and multipass configurations. Multipass configurations have much higher selectivity and are needed for measurements where there is a large amount of excess noise caused by stray laser light. It is shown that Rayleigh scattering is particularly useful for supersonic and hypersonic flows. The results of the analysis are compared with measurements obtained with a Rayleigh scattering diagnostic developed for study of the exhaust plume of a small hydrogen-oxygen rocket, where the velocities are in the range of 1000 to 5000 m/sec.

  3. Thomson Scattering Density Calibration by Rayleigh and Rotational Raman Scattering on NSTX

    SciTech Connect

    B.P. LeBlanc

    2008-07-16

    The multi-point Thomson scattering (MPTS) diagnostic measures the profiles of the electron temperature Te(R) and density ne(R) on the horizontal midplane of NSTX. Normal operation makes use of Rayleigh scattering in nitrogen or argon to derive the density profile. While the Rayleigh scattering ne(R) calibration has been validated by comparison with other density measurements and through its correlation with plasma phenomena, it does require dedicated detectors at the laser wavelength in this filter polychromator based diagnostic. The presence of dust and/or stray laser light precludes routine use of these dedicated spectral channels for Thomson scattering measurement. Hence it is of interest to investigate the use of Raman scattering in nitrogen for the purpose of density calibration, since it could free up detection equipment, which could then be used for the instrumentation of additional radial channels. In this paper the viewing optics "geometrical factor" profiles obtained from Rayleigh and Raman scattering are compared. While both techniques agree nominally, residual effects on the order of 10% remain and will be discussed.

  4. Rayleigh scattering: blue sky thinking for future CMB observations

    SciTech Connect

    Lewis, Antony

    2013-08-01

    Rayleigh scattering from neutral hydrogen during and shortly after recombination causes the CMB anisotropies to be significantly frequency dependent at high frequencies. This may be detectable with Planck, and would be a strong signal in any future space-based CMB missions. The later peak of the Rayleigh visibility compared to Thomson scattering gives an increased large-scale CMB polarization signal that is a greater than 4% effect for observed frequencies ν ∼> 500GHz. There is a similar magnitude suppression on small scales from additional damping. Due to strong correlation between the Rayleigh and primary signal, measurement of the Rayleigh component is limited by noise and foregrounds, not cosmic variance of the primary CMB, and should observable over a wide range of angular scales at frequencies 200GHz ∼< ν ∼< 800GHz. I give new numerical calculations of the temperature and polarization power spectra, and show that future CMB missions could measure the temperature Rayleigh cross-spectrum at high precision, detect the polarization from Rayleigh scattering, and also accurately determine the cross-spectra between the Rayleigh temperature signal and primary polarization. The Rayleigh scattering signal may provide a powerful consistency check on recombination physics. In principle it can be used to measure additional horizon-scale primordial perturbation modes at recombination, and distinguish a significant tensor mode B-polarization signal from gravitational lensing at the power spectrum level.

  5. Study of Injection of Helium into Supersonic Air Flow Using Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Seaholtz, Richard G.; Buggele, Alvin E.

    1997-01-01

    A study of the transverse injection of helium into a Mach 3 crossflow is presented. Filtered Rayleigh scattering is used to measure penetration and helium mole fraction in the mixing region. The method is based on planar molecular Rayleigh scattering using an injection-seeded, frequency-doubled ND:YAG pulsed laser and a cooled CCD camera. The scattered light is filtered with an iodine absorption cell to suppress stray laser light. Preliminary data are presented for helium mole fraction and penetration. Flow visualization images obtained with a shadowgraph and wall static pressure data in the vicinity of the injection are also presented.

  6. Mechanisms universally permitting hyper-Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Williams, Mathew D.; Ford, Jack S.; Andrews, David L.

    2015-02-01

    Hyper-Rayleigh scattering (HRS) is an incoherent variant of second harmonic generation. The theory involves terms of increasing order of optical nonlinearity: for molecules or unit cells that are centrosymmetric, and which accordingly lack even-order susceptibilities, HRS is often regarded as formally forbidden. However, for the three-photon interaction, theory based on the standard electric dipole approximation, represented as E13, does not include the detail required to describe what is observed experimentally, in the absence of a static field. New results emerge upon extending the theory to include E12E2 and E12M1, incorporating one electric quadrupolar or magnetic dipolar interaction respectively. Both additional interactions require the deployment of higher orders in the multipole expansion to govern these processes, with the E12E2 interaction analogous in rank and parity to a four-wave susceptibility. A key feature of the present work is its foundation upon a formal tensor derivation which does not oversimplify the molecular components, yet leads to results whose interpretation can be correlated with experimental observations. Results are summarized for the perpendicular detection of both parallel and perpendicular polarizations. Using such methods to investigate molecular systems that might have useful nonlinear characteristics, HRS therefore provides a route to data with direct physical interpretation, to enable more sophisticated design of molecules with sought optical properties.

  7. Rayleigh scattering in the atmospheres of hot stars

    NASA Astrophysics Data System (ADS)

    Fišák, J.; Krtička, J.; Munzar, D.; Kubát, J.

    2016-05-01

    Context. Rayleigh scattering is a result of an interaction of photons with bound electrons. Rayleigh scattering is mostly neglected in calculations of hot star model atmospheres because most of the hydrogen atoms are ionized and the heavier elements have a lower abundance than hydrogen. In atmospheres of some chemically peculiar stars, helium overabundant regions containing singly ionized helium are present and Rayleigh scattering can be a significant opacity source. Aims: We evaluate the contribution of Rayleigh scattering by neutral hydrogen and singly ionized helium in the atmospheres of hot stars with solar composition and in the atmospheres of helium overabundant stars. Methods: We computed several series of model atmospheres using the TLUSTY code and emergent fluxes using the SYNSPEC code. These models describe atmospheres of main sequence B-type stars with different helium abundance. We used an existing grid of models for atmospheres with solar chemical composition and we calculated an additional grid for helium-rich stars with N(He)/N(H) = 10. Results: Rayleigh scattering by neutral hydrogen can be neglected in atmospheres of hot stars, while Rayleigh scattering by singly ionized helium can be a non-negligible opacity source in some hot stars, especially in helium-rich stars.

  8. Gas temperature measurements using the dual-line detection Rayleigh scattering technique

    NASA Technical Reports Server (NTRS)

    Otugen, M. Volkan; Seasholtz, Richard G.; Annen, Kurt D.

    1992-01-01

    A new laser-induced Rayleigh scattering method is presented for the improved temperature diagnostics of gas flows. In the present technique, the two lines of a copper vapor laser are used to obtain the time and space resolved temperature. A single set of optics is used to form the optical probe and to collect the signal simultaneously from both the 510 nm and the 578 nm lines. The dual-line detection allows for the determination and removal of surface-scattered laser light from a Rayleigh signal thereby improving the applicability of Rayleigh scattering to near wall flows with a high degree of glare. An optical system using the dual-line detection technique is built, calibrated and tested in a hot air jet under various levels of background contamination. The results indicate that highly accurate temperature measurements are possible even when the laser-line background intensity, captured by the collecting optics, is five times that of the Rayleigh signal.

  9. Correction of Rayleigh Scattering Effects in Cloud Optical Thickness Retrievals

    NASA Technical Reports Server (NTRS)

    Wang, Meng-Hua; King, Michael D.

    1997-01-01

    We present results that demonstrate the effects of Rayleigh scattering on the 9 retrieval of cloud optical thickness at a visible wavelength (0.66 Am). The sensor-measured radiance at a visible wavelength (0.66 Am) is usually used to infer remotely the cloud optical thickness from aircraft or satellite instruments. For example, we find that without removing Rayleigh scattering effects, errors in the retrieved cloud optical thickness for a thin water cloud layer (T = 2.0) range from 15 to 60%, depending on solar zenith angle and viewing geometry. For an optically thick cloud (T = 10), on the other hand, errors can range from 10 to 60% for large solar zenith angles (0-60 deg) because of enhanced Rayleigh scattering. It is therefore particularly important to correct for Rayleigh scattering contributions to the reflected signal from a cloud layer both (1) for the case of thin clouds and (2) for large solar zenith angles and all clouds. On the basis of the single scattering approximation, we propose an iterative method for effectively removing Rayleigh scattering contributions from the measured radiance signal in cloud optical thickness retrievals. The proposed correction algorithm works very well and can easily be incorporated into any cloud retrieval algorithm. The Rayleigh correction method is applicable to cloud at any pressure, providing that the cloud top pressure is known to within +/- 100 bPa. With the Rayleigh correction the errors in retrieved cloud optical thickness are usually reduced to within 3%. In cases of both thin cloud layers and thick ,clouds with large solar zenith angles, the errors are usually reduced by a factor of about 2 to over 10. The Rayleigh correction algorithm has been tested with simulations for realistic cloud optical and microphysical properties with different solar and viewing geometries. We apply the Rayleigh correction algorithm to the cloud optical thickness retrievals from experimental data obtained during the Atlantic

  10. Light spin forces in optical traps: comment on "Trapping metallic Rayleigh particles with radial polarization".

    PubMed

    Iglesias, Ignacio; Sáenz, Juan José

    2012-01-30

    An incomplete modeling of the scattering forces on a Rayleigh particle without taking into account the light spin forces in "Trapping metallic Rayleigh particles with radial polarization" by Q. Zhan, leads to erroneous statements on the advantages of using radial polarization to trap metallic particles. PMID:22330519

  11. Demonstration and Analysis of Filtered Rayleigh Scattering Flow Field Diagnostic System

    NASA Technical Reports Server (NTRS)

    Forkey, Joseph N.; Lempert, Walter R.; Miles, Richard B.

    1996-01-01

    Filtered Rayleigh Scattering (FRS) is a diagnostic technique which measures velocity, temperature, and pressure by determining Doppler shift, total intensity, and spectral line shape of laser induced Rayleigh-Brillouin scattering. In the work reported here, this is accomplished by using a narrow line width, injection seeded Nd-YAG laser sheet to induce Rayleigh-Brillouin scattering from a gas flow. This light is passed through an optical notch filter, and transmitted light is imaged onto an intensified charge coupled display (CCD) camera. By monitoring the grayscale value at a particular pixel while the laser frequency is tuned, the convolution between the Rayleigh-Brillouin scattering profile and the filter transmission profile is attained. Since the filter profile can be independently measured, it can be deconvolved from the measuring signal, yielding the Rayleigh-Brillouin scattering profile. From this profile, flow velocity, temperature, and pressure are determined. In this paper the construction and characterization of the optical notch filter and a newly developed frequency apparatus are discussed.

  12. Rayleigh scattering in few-mode optical fibers

    PubMed Central

    Wang, Zhen; Wu, Hao; Hu, Xiaolong; Zhao, Ningbo; Mo, Qi; Li, Guifang

    2016-01-01

    The extremely low loss of silica fibers has enabled the telecommunication revolution, but single-mode fiber-optic communication systems have been driven to their capacity limits. As a means to overcome this capacity crunch, space-division multiplexing (SDM) using few-mode fibers (FMF) has been proposed and demonstrated. In single-mode optical fibers, Rayleigh scattering serves as the dominant mechanism for optical loss. However, to date, the role of Rayleigh scattering in FMFs remains elusive. Here we establish and experimentally validate a general model for Rayleigh scattering in FMFs. Rayleigh backscattering not only sets the intrinsic loss limit for FMFs but also provides the theoretical foundation for few-mode optical time-domain reflectometry, which can be used to probe perturbation-induced mode-coupling dynamics in FMFs. We also show that forward inter-modal Rayleigh scattering ultimately sets a fundamental limit on inter-modal-crosstalk for FMFs. Therefore, this work not only has implications specifically for SDM systems but also broadly for few-mode fiber optics and its applications in amplifiers, lasers, and sensors in which inter-modal crosstalk imposes a fundamental performance limitation. PMID:27775003

  13. Control of experimental uncertainties in filtered Rayleigh scattering measurements

    NASA Technical Reports Server (NTRS)

    Forkey, Joseph N.; Finkelstein, N. D.; Lempert, Walter R.; Miles, Richard B.

    1995-01-01

    Filtered Rayleigh Scattering is a technique which allows for measurement of velocity, temperature, and pressure in unseeded flows, spatially resolved in 2-dimensions. We present an overview of the major components of a Filtered Rayleigh Scattering system. In particular, we develop and discuss a detailed theoretical model along with associated model parameters and related uncertainties. Based on this model, we then present experimental results for ambient room air and for a Mach 2 free jet, including spatially resolved measurements of velocity, temperature, and pressure.

  14. Horizontal lidar measurements for the proof of spontaneous Rayleigh-Brillouin scattering in the atmosphere.

    PubMed

    Witschas, Benjamin; Lemmerz, Christian; Reitebuch, Oliver

    2012-09-01

    Several atmospheric lidar techniques rely on the exact knowledge of the spectral line shape of molecular scattered light in air, which, however, has not been accurately measured in real atmosphere up to now. In this paper we report on the investigation of spontaneous Rayleigh-Brillouin scattering within the atmosphere, utilizing horizontal lidar measurements (λ=355 nm, θ=180°) performed from the mountain observatory Schneefernerhaus (2650 m), located below Germany's highest mountain, the Zugspitze. These lidar measurements give proof of the effect of Brillouin scattering within the atmosphere for the first time to our knowledge. The measurements confirm that the Tenti S6 model can be used to adequately describe spontaneous Rayleigh-Brillouin spectra of light scattered in air under real atmospheric conditions. The presented results are of relevance for spectrally resolving lidars like those deployed on the Atmospheric Dynamics Mission Aeolus (ADM-Aeolus) andthe Earth Clouds, Aerosols, and Radiation Explorer Mission (EarthCARE).

  15. Flow Visualization of Density in a Cryogenic Wind Tunnel Using Planar Rayleigh and Raman Scattering

    NASA Technical Reports Server (NTRS)

    Herring, Gregory C.; Shirinzadeh, Behrooz

    2002-01-01

    Using a pulsed Nd:YAG laser (532 nm) and a gated, intensified charge-coupled device, planar Rayleigh and Raman scattering techniques have been used to visualize the unseeded Mach 0.2 flow density in a 0.3-meter transonic cryogenic wind tunnel. Detection limits are determined for density measurements by using both unseeded Rayleigh and Raman (N2 vibrational) methods. Seeding with CO2 improved the Rayleigh flow visualization at temperatures below 150 K. The seeded Rayleigh version was used to demonstrate the observation of transient flow features in a separated boundary layer region, which was excited with an oscillatory jet. Finally, a significant degradation of the laser light sheet, in this cryogenic facility, is discussed.

  16. Rayleigh scattering from argon clusters in a planar expansion

    SciTech Connect

    DeArmond, F. M.; Suelzer, J.; Masters, M. F.

    2008-05-01

    Rayleigh scattering is presented as evidence for the presence of large argon clusters formed in a planar expansion. Based on the observed scattering signal, the dependence of mean cluster size on stagnation pressure is {proportional_to}P{sub 0}{sup 3.38}. This is in contrast to the dependence of the mean cluster size on stagnation pressure for a symmetric expansion of {proportional_to}P{sub 0}{sup 2.29}.

  17. Rayleigh scattering of a spherical sound wave.

    PubMed

    Godin, Oleg A

    2013-02-01

    Acoustic Green's functions for a homogeneous medium with an embedded spherical obstacle arise in analyses of scattering by objects on or near an interface, radiation by finite sources, sound attenuation in and scattering from clouds of suspended particles, etc. An exact solution of the problem of diffraction of a monochromatic spherical sound wave on a sphere is given by an infinite series involving products of Bessel functions and Legendre polynomials. In this paper, a simple, closed-form solution is obtained for scattering by a sphere with a radius that is small compared to the wavelength. Soft, hard, impedance, and fluid obstacles are considered. The solution is valid for arbitrary positions of the source and receiver relative to the scatterer. Low-frequency scattering is shown to be rather sensitive to boundary conditions on the surface of the obstacle. Low-frequency asymptotics of the scattered acoustic field are extended to transient incident waves. The asymptotic expansions admit an intuitive interpretation in terms of image sources and reduce to classical results in appropriate limiting cases.

  18. Study of Fabry-Perot Etalon Stability and Tuning for Spectroscopic Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Clem, Michelle M.; Mielke-Fagan, Amy F.; Elam, Kristie A.

    2010-01-01

    The Fabry-Perot interferometer is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating flow properties such as gas velocity and temperature. Rayleigh scattered light from a focused laser beam can be directly imaged through a solid Fabry-Perot etalon onto a CCD detector to provide the spectral content of the scattered light. The spatial resolution of the measurements is governed by the locations of interference fringes. The location of the fringes can be changed by altering the etalon?s physical characteristics, such as thickness and index of refraction. For a fused silica solid etalon the physical properties can be adjusted by changing the etalon temperature; hence changing the order of the interference pattern and the physical fringe locations. Controlling the temperature of the etalon can provide for a slow time-response spatial scanning method for this type of etalon system. A custom designed liquid crystal Fabry-Perot (LCFP) can provide for a fast time-response method of scanning the etalon system. Voltage applied to the liquid crystal interface sets the etalon?s properties allowing Rayleigh measurements to be acquired at varying spatial locations across the image of the laser beam over a very short time period. A standard fused silica etalon and a tunable LCFP etalon are characterized to select the system that is best suited for Rayleigh scattering measurements in subsonic and supersonic flow regimes. A frequency-stabilized laser is used to investigate the apparent frequency stability and temperature sensitivity of the etalon systems. Frequency stability and temperature sensitivity data of the fused silica and LCFP etalon systems are presented in this paper, along with measurements of the LCFP etalon?s tuning capabilities. Rayleigh scattering velocity measurements with both etalon systems are presented, in an effort to determine which etalon is better suited to provide optical flow

  19. Errors induced by the neglect of polarization in radiance calculations for Rayleigh-scattering atmospheres

    NASA Technical Reports Server (NTRS)

    Mishchenko, M. I.; Lacis, A. A.; Travis, L. D.

    1994-01-01

    Although neglecting polarization and replacing the rigorous vector radiative transfer equation by its approximate scalar counterpart has no physical background, it is a widely used simplification when the incident light is unpolarized and only the intensity of the reflected light is to be computed. We employ accurate vector and scalar multiple-scattering calculations to perform a systematic study of the errors induced by the neglect of polarization in radiance calculations for a homogeneous, plane-parallel Rayleigh-scattering atmosphere (with and without depolarization) above a Lambertian surface. Specifically, we calculate percent errors in the reflected intensity for various directions of light incidence and reflection, optical thicknesses of the atmosphere, single-scattering albedos, depolarization factors, and surface albedos. The numerical data displayed can be used to decide whether or not the scalar approximation may be employed depending on the parameters of the problem. We show that the errors decrease with increasing depolarization factor and/or increasing surface albedo. For conservative or nearly conservative scattering and small surface albedos, the errors are maximum at optical thicknesses of about 1. The calculated errors may be too large for some practical applications, and, therefore, rigorous vector calculations should be employed whenever possible. However, if approximate scalar calculations are used, we recommend to avoid geometries involving phase angles equal or close to 0 deg and 90 deg, where the errors are especially significant. We propose a theoretical explanation of the large vector/scalar differences in the case of Rayleigh scattering. According to this explanation, the differences are caused by the particular structure of the Rayleigh scattering matrix and come from lower-order (except first-order) light scattering paths involving right scattering angles and right-angle rotations of the scattering plane.

  20. Cavity-modified collective Rayleigh scattering of two atoms.

    PubMed

    Reimann, René; Alt, Wolfgang; Kampschulte, Tobias; Macha, Tobias; Ratschbacher, Lothar; Thau, Natalie; Yoon, Seokchan; Meschede, Dieter

    2015-01-16

    We report on the observation of cooperative radiation of exactly two neutral atoms strongly coupled to the single mode field of an optical cavity, which is close to the lossless-cavity limit. Monitoring the cavity output power, we observe constructive and destructive interference of collective Rayleigh scattering for certain relative distances between the two atoms. Because of cavity backaction onto the atoms, the cavity output power for the constructive two-atom case (N=2) is almost equal to the single-emitter case (N=1), which is in contrast to free-space where one would expect an N^{2} scaling of the power. These effects are quantitatively explained by a classical model as well as by a quantum mechanical model based on Dicke states. We extract information on the relative phases of the light fields at the atom positions and employ advanced cooling to reduce the jump rate between the constructive and destructive atom configurations. Thereby we improve the control over the system to a level where the implementation of two-atom entanglement schemes involving optical cavities becomes realistic. PMID:25635545

  1. Dual-Line Detection Rayleigh Scattering Measurements of Density and Temperature

    NASA Technical Reports Server (NTRS)

    Annen, Kurt; Otugen, Volkan; Seasholtz, Richard

    1996-01-01

    Measurements of the laser Rayleigh scattering signal in a flow to determine density and temperature have been commonly employed in open flames and in wind tunnel environments. In these measurements, the density or reciprocal temperature is correlated with the Rayleigh scattering signal intensity. A major advantage of Rayleigh scattering for these applications is the simple experimental arrangement allowed by this technique. Intensity-based Rayleigh scattering measurements of density and temperature have been limited to relatively clean flows in open environments so that interference from particle scattering and laser scattering is minimal. A new approach, using dual-line detection Rayleigh (DLDR) scattering extends the applicability of Rayleigh scattering measurements of density and temperature to enclosed environments where surface scattering interference is high. Depending on particle size and optical properties, this approach may also reduce interference from particle scattering.

  2. Rayleigh scattering and nonlinear inversion of elastic waves

    SciTech Connect

    Gritto, R.

    1995-12-01

    Rayleigh scattering of elastic waves by an inclusion is investigated and the limitations determined. In the near field of the inhomogeneity, the scattered waves are up to a factor of 300 stronger than in the far field, excluding the application of the far field Rayleigh approximation for this range. The investigation of the relative error as a function of parameter perturbation shows a range of applicability broader than previously assumed, with errors of 37% and 17% for perturbations of {minus}100% and +100%, respectively. The validity range for the Rayleigh limit is controlled by large inequalities, and therefore, the exact limit is determined as a function of various parameter configurations, resulting in surprisingly high values of up to k{sub p}R = 0.9. The nonlinear scattering problem can be solved by inverting for equivalent source terms (moments) of the scatterer, before the elastic parameters are determined. The nonlinear dependence between the moments and the elastic parameters reveals a strong asymmetry around the origin, which will produce different results for weak scattering approximations depending on the sign of the anomaly. Numerical modeling of cross hole situations shows that near field terms are important to yield correct estimates of the inhomogeneities in the vicinity of the receivers, while a few well positioned sources and receivers considerably increase the angular coverage, and thus the model resolution of the inversion parameters. The pattern of scattered energy by an inhomogeneity is complicated and varies depending on the object, the wavelength of the incident wave, and the elastic parameters involved. Therefore, it is necessary to investigate the direction of scattered amplitudes to determine the best survey geometry.

  3. Linear approximation of Rayleigh-Brillouin scattering spectra.

    PubMed

    Binietoglou, Ioannis; Giampouras, Paris; Belegante, Livio

    2016-09-20

    Rayleigh-Brillouin scattering is the basis of many remote sensing techniques, including high spectral resolution lidar measurements of aerosols and wind. Rayleigh-Brillouin spectra can be accurately estimated using physics-based models like the so-called Tenti's S6 and Pan's S7 models. Unfortunately, these are computationally expensive and can be the bottleneck for real-time lidar processing and iterative parameter estimation problems. This short article describes a very efficient linear approximation of the Rayleigh-Brillouin spectra based on Principal Component Analysis (PCA). Using PCA, the outputs of the above models can be approximated with very high accuracy using a single matrix multiplication. The described method can be applied to the output of any detailed scattering model, thus it can be used for a wide range of problems, e.g., for scattering from different gases (Air, N2, O2,…) and for different ranges of temperature and pressure. The precision of the approximation can be adapted to the requirements of the studied problem, and can easily exceed the actual accuracy of the reference models. PMID:27661601

  4. On the critical role of Rayleigh scattering in single-molecule surface-enhanced Raman scattering via a plasmonic nanogap.

    PubMed

    Chen, Bao-Qin; Zhang, Chao; Li, Jiafang; Li, Zhi-Yuan; Xia, Younan

    2016-08-25

    Electromagnetic and chemical enhancement mechanisms are commonly used to account for single-molecule surface-enhanced Raman scattering (SM-SERS). Due to many practical limitations, however, the overall enhancement factor summed up from these two mechanisms is typically 5-6 orders of magnitude below the level of 10(14)-10(15) required for SM-SERS. Here, we demonstrate that the multiple elastic Rayleigh scattering of a molecule could play a critical role in further enhancing the Raman signal, when the molecule is trapped in a 2 nm gap between two Ag nanoparticles, pushing the overall enhancement factor close to the level needed for SM-SERS. As a universal physical process for all molecules interacting with light, we believe that Rayleigh scattering plays a pivotal and as yet unrecognized role in SERS, in particular, for enabling single-molecule sensitivity. PMID:27526632

  5. Rayleigh Scattering Diagnostic for Simultaneous Measurements of Dynamic Density and Velocity

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Panda, J.

    2000-01-01

    A flow diagnostic technique based on the molecular Rayleigh scattering of laser light is used to obtain dynamic density and velocity data in turbulent flows. The technique is based on analyzing the Rayleigh scattered light with a Fabry-Perot interferometer and recording information about the interference pattern with a multiple anode photomultiplier tube (PMT). An artificial neural network is used to process the signals from the PMT to recover the velocity time history, which is then used to calculate the velocity power spectrum. The technique is illustrated using simulated data. The results of an experiment to measure the velocity power spectrum in a low speed (100 rn/sec) flow are also presented.

  6. Rayleigh Scattering Diagnostic for Dynamic Measurement of Velocity Fluctuations in High Speed Jets

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Panda, Jayanta; Elam, Kristie A.

    2001-01-01

    A flow diagnostic technique based on the molecular Rayleigh scattering of laser light is used to obtain dynamic density and velocity data in a high speed flow. The technique is based on analyzing the Rayleigh scattered light with a Fabry-Perot interferometer used in the static, imaging mode. An analysis is presented that established a lower bound for measurement uncertainty of about 20 m/sec for individual velocity measurements obtained in a 100 microsecond time interval. Software and hardware interfaces were developed to allow computer control of all aspects of the experiment and data acquisition. The signals from three photomultiplier tubes were simultaneously recorded using photon counting at a 10 kHz sampling rate and 10 second recording periods. Density and velocity data, including distribution functions and power spectra, taken in a Mach 0.8 free jet, are presented.

  7. Apparatus and Method for Measuring Strain in Optical Fibers using Rayleigh Scatter

    NASA Technical Reports Server (NTRS)

    Froggatt, Mark E. (Inventor); Moore, Jason P. (Inventor)

    2003-01-01

    An apparatus and method for measuring strain in an optical fiber using the spectral shift of Rayleigh scattered light. The interference pattern produced by an air gap reflector and backscattered radiation is measured. Using Fourier Transforms, the spectrum of any section of fiber can be extracted. Cross correlation with an unstrained measurement produces a correlation peak. The location of the correlation peak indicates the strain level in the selected portion of optical fiber.

  8. Laser scattering on an atmospheric pressure plasma jet: disentangling Rayleigh, Raman and Thomson scattering

    NASA Astrophysics Data System (ADS)

    van Gessel, A. F. H.; Carbone, E. A. D.; Bruggeman, P. J.; van der Mullen, J. J. A. M.

    2012-02-01

    Laser scattering provides a very direct method for measuring the local densities and temperatures inside a plasma. We present new experimental results of laser scattering on an argon atmospheric pressure microwave plasma jet operating in an air environment. The plasma is very small so a high spatial resolution is required to study the effect of the penetration of air molecules into the plasma. The scattering signal has three overlapping contributions: Rayleigh scattering from heavy particles, Thomson scattering from free electrons and Raman scattering from molecules. The Rayleigh scattering signal is filtered out optically with a triple grating spectrometer. The disentanglement of the Thomson and Raman signals is done with a newly designed fitting method. With a single measurement we determine profiles of the electron temperature, electron density, gas temperature, partial air pressure and the N2/O2 ratio, with a spatial resolution of 50 µm, and including absolute calibration.

  9. Setting up a Rayleigh Scattering Based Flow Measuring System in a Large Nozzle Testing Facility

    NASA Technical Reports Server (NTRS)

    Panda, Jayanta; Gomez, Carlos R.

    2002-01-01

    A molecular Rayleigh scattering based air density measurement system has been built in a large nozzle testing facility at NASA Glenn Research Center. The technique depends on the light scattering by gas molecules present in air; no artificial seeding is required. Light from a single mode, continuous wave laser was transmitted to the nozzle facility by optical fiber, and light scattered by gas molecules, at various points along the laser beam, is collected and measured by photon-counting electronics. By placing the laser beam and collection optics on synchronized traversing units, the point measurement technique is made effective for surveying density variation over a cross-section of the nozzle plume. Various difficulties associated with dust particles, stray light, high noise level and vibration are discussed. Finally, a limited amount of data from an underexpanded jet are presented and compared with expected variations to validate the technique.

  10. An equipment for Rayleigh scattering of Mössbauer radiation

    NASA Astrophysics Data System (ADS)

    Enescu, S. E.; Bibicu, I.; Zoran, V.; Kluger, A.; Stoica, A. D.; Tripadus, V.

    1998-07-01

    A personal computer driven equipment designed for Rayleigh scattering of Mössbauer radiation experiments at room temperature is described. The performances of the system were tested using like scatterers crystals with different mosaic divergences: lithium fluoride (LiF) and pyrolytic graphite (C). The equipment, suitable for any kind of Mössbauer scattering experiments, permits low and adjustable horizontal divergences of the incident beam. On décrit un équipement dédié aux mesures de diffusion Rayleigh de la radiation Mössbauer controlée par ordinateur. Les performances du système ont été testées sur des cristaux ayant des divergences de mosaïque différentes: le fluorure de lithium (LiF) et le graphite pyrolytique (C). L'équipement, qui peut être utilisé dans des différents types d'expérimentations basées sur la diffusion de la radiation Mössbauer, admet des divergences horizontales du faisceau incident faibles et réglables.

  11. Rayleigh Scattering Diagnostic for Measurement of Velocity and Density Fluctuation Spectra

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Panda, Jayanta; Elam, Kristie A.

    2002-01-01

    A new molecular Rayleigh scattering based flow diagnostic is used for the first time to measure the power spectrum of gas density and radial velocity component in the plumes of high speed jets. The technique is based on analyzing the Rayleigh scattered light with a Fabry-Perot interferometer used in the static, imaging mode. The PC based data acquisition system is capable of simultaneous sampling of velocity and density at rates to 100 kHz and data record lengths to 10 million. Velocity and density power spectra and velocity-density cross spectra are presented for a subsonic jet, an underexpanded screeching jet, and for Mach 1.4 and Mach 1.8 supersonic jets. Software and hardware interfaces were developed to allow computer control of all aspects of the experiment and data acquisition.

  12. Dynamics of macroscopic fluctuations in aqueous systems according to Rayleigh scattering data

    NASA Astrophysics Data System (ADS)

    Belovolova, L. V.; Glushkov, M. V.; Timashev, S. F.

    2015-09-01

    The general question of the existence of macrofluctuations of physical characteristics of aqueous systems are discussed. Using the example of analyzing fluctuations in the Rayleigh scattering of natural untreated water, along with catholyte and anolyte obtained in its electrochemical treatment, the possibility of obtaining of quantitative information on the states and dynamics of changes in such systems is shown. Data on the parameters of oscillations in the Rayleigh light scattering of water catholyte and anolyte immediately after electrolysis, and one and two days after its completion, are presented. Calculations are performed using the general phenomenological approach to analyzing chaotic signals (flicker-noise spectroscopy). Quantitative characteristics that reveal substantial differences in the dynamics of macrofluctuations that develop in the catholyte and anolyte of the studied water are presented.

  13. Velocity and Temperature Measurement in Supersonic Free Jets Using Spectrally Resolved Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Panda, J.; Seasholtz, R. G.

    2004-01-01

    The flow fields of unheated, supersonic free jets from convergent and convergent-divergent nozzles operating at M = 0.99, 1.4, and 1.6 were measured using spectrally resolved Rayleigh scattering technique. The axial component of velocity and temperature data as well as density data obtained from a previous experiment are presented in a systematic way with the goal of producing a database useful for validating computational fluid dynamics codes. The Rayleigh scattering process from air molecules provides a fundamental means of measuring flow properties in a non-intrusive, particle free manner. In the spectrally resolved application, laser light scattered by the air molecules is collected and analyzed using a Fabry-Perot interferometer (FPI). The difference between the incident laser frequency and the peak of the Rayleigh spectrum provides a measure of gas velocity. The temperature is measured from the spectral broadening caused by the random thermal motion and density is measured from the total light intensity. The present point measurement technique uses a CW laser, a scanning FPI and photon counting electronics. The 1 mm long probe volume is moved from point to point to survey the flow fields. Additional arrangements were made to remove particles from the main as well as the entrained flow and to isolate FPI from the high sound and vibration levels produced by the supersonic jets. In general, velocity is measured within +/- 10 m/s accuracy and temperature within +/- 10 K accuracy.

  14. Analytical evaluation of atomic form factors: Application to Rayleigh scattering

    SciTech Connect

    Safari, L.; Santos, J. P.; Amaro, P.; Jänkälä, K.; Fratini, F.

    2015-05-15

    Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.

  15. Multiple Point Dynamic Gas Density Measurements Using Molecular Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard; Panda, Jayanta

    1999-01-01

    A nonintrusive technique for measuring dynamic gas density properties is described. Molecular Rayleigh scattering is used to measure the time-history of gas density simultaneously at eight spatial locations at a 50 kHz sampling rate. The data are analyzed using the Welch method of modified periodograms to reduce measurement uncertainty. Cross-correlations, power spectral density functions, cross-spectral density functions, and coherence functions may be obtained from the data. The technique is demonstrated using low speed co-flowing jets with a heated inner jet.

  16. Spatially-and Temporally-Resolved Multi-Parameter Interferometric Rayleigh Scattering System and Method

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel (Inventor); Cutler, Andrew D. (Inventor); Danehy, Paul M. (Inventor)

    2015-01-01

    A system that simultaneously measures the translational temperature, bulk velocity, and density in gases by collecting, referencing, and analyzing nanosecond time-scale Rayleigh scattered light from molecules is described. A narrow-band pulsed laser source is used to probe two largely separated measurement locations, one of which is used for reference. The elastically scattered photons containing information from both measurement locations are collected at the same time and analyzed spectrally using a planar Fabry-Perot interferometer. A practical means of referencing the measurement of velocity using the laser frequency, and the density and temperature using the information from the reference measurement location maintained at constant properties is provided.

  17. Intracavity Rayleigh/Mie Scattering for Multipoint, Two-Component Velocity Measurement

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Lee, Joseph W.

    2006-01-01

    A simultaneous multi-point two-component Doppler velocimeter is described. The system uses two optical cavities: a Fabry-Perot etalon and an optical cavity for collecting and re-circulating the Rayleigh/Mie scattered light that is collected from the measurement volume in two parallel, but opposite directions. Single-pulse measurements of two orthogonal components of the velocity vector in a supersonic free jet were performed to demonstrate the technique. The re-circulation of the light rejected by the interferometer input mirror also increased the signal intensity by a factor of 3.5. 2005 Optical Society of America Interferometric Rayleigh scattering has previously been used for single-point velocity measurements in unseeded gas flow. However, this past work has generally been limited to probing with continuous-wave lasers resulting in time-averaged measurements of velocity. Multiple velocity components have been measured simultaneously by separate instruments.1,2 It has also been demonstrated that two orthogonal velocity components can be measured simultaneously at one point using one interferometer by reflecting back the probing laser beam, although this approach results in directional ambiguity of the flow velocity vector.3 This measurement ambiguity was removed by prior knowledge of the approximate magnitude and sign of the velocity components. Furthermore, it was shown that multiple points could be measured simultaneously with a Rayleigh scattering interferometric approach, but only one component of velocity was measured.4 Another method of performing multiple component velocity measurements with Rayleigh scattering uses a pair of cameras to image the flow, one of which views the flow through an iodine gas filter. This iodine-filter technique has the advantage of allowing high-resolution velocity imaging, but it generally has a lower dynamic range.

  18. Single-pulse Multi-point Multi-component Interferometric Rayleigh Scattering Velocimeter

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Lee, Joseph W.; Gaffney, Richard L., Jr.; Cutler, Andrew W.

    2006-01-01

    A simultaneous multi-point, multi-component velocimeter using interferometric detection of the Doppler shift of Rayleigh, Mie, and Rayleigh-Brillouin scattered light in supersonic flow is described. The system uses up to three sets of collection optics and one beam combiner for the reference laser light to form a single collimated beam. The planar Fabry-Perot interferometer used in the imaging mode for frequency detection preserves the spatial distribution of the signal reasonably well. Single-pulse multi-points measurements of up to two orthogonal and one non-orthogonal components of velocity in a Mach 2 free jet were performed to demonstrate the technique. The average velocity measurements show a close agreement with the CFD calculations using the VULCAN code.

  19. Instantaneous 2D Velocity and Temperature Measurements in High Speed Flows Based on Spectrally Resolved Molecular Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.

    1995-01-01

    A Rayleigh scattering diagnostic for high speed flows is described for the simultaneous, instantaneous measurement of gas temperature and velocity at a number (up to about one hundred) of locations in a plane illuminated by an injection-seeded, frequency doubled Nd:YAG laser. Molecular Rayleigh scattered light is collected and passed through a planar mirror Fabry-Perot interferometer. The resulting image is analyzed to determine the gas temperature and bulk velocity at each of the regions. The Cramer Rao lower bound for measurement uncertainty is calculated. Experimental data is presented for a free jet and for preliminary measurements in the Lewis 4 inch by 10 inch supersonic wind tunnel.

  20. Direct-View Multi-Point Two-Component Interferometric Rayleigh Scattering Velocimeter

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Gaffney, Richard L., Jr.; Cutler, Andrew D.

    2008-01-01

    This paper describes an instantaneous velocity measurement system based on the Doppler shift of elastically scattered laser light from gas molecules (Rayleigh scattering) relative to an incident laser. The system uses a pulsed laser as the light source, direct-viewing optics to collect the scattered light, an interferometer to analyze spectrally the scattered light mixed with the incident laser light, and a CCD camera to capture the resulting interferogram. The system is capable of simultaneous, spatially (approximately 0.2 mm(exp 3)) and temporally (approximately 40 ns) resolved, multiple point measurements of two orthogonal components of flow velocity in the presence of background scattered light, acoustic noise and vibrations, and flow particulates. Measurements in a large-scale axi-symmetric Mach 1.6 H2-air combustion-heated jet running at a flow sensible enthalpy specific to Mach 5.5 hypersonic flight are performed to demonstrate the technique. The measurements are compared with CFD calculations using a finite-volume discretization of the Favre-averaged Navier-Stokes equations (VULCAN code).

  1. Molecular Rayleigh Scattering Diagnostic for Dynamic Temperature, Velocity, and Density Measurements

    NASA Technical Reports Server (NTRS)

    Mielke, Amy R.; Elam, Kristie A.; Sung, Chi-Jen

    2006-01-01

    A molecular Rayleigh scattering technique is developed to measure dynamic gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 16 kHz. A high power CW laser beam is focused at a point in an air jet plume and Rayleigh scattered light is collected and spectrally resolved. The spectrum of the light, which contains information about the temperature and velocity of the flow, is analyzed using a Fabry-Perot interferometer. The circular interference fringe pattern is divided into four concentric regions and sampled at 1 and 16 kHz using photon counting electronics. Monitoring the relative change in intensity within each region allows for measurement of gas temperature and velocity. Independently monitoring the total scattered light intensity provides a measure of gas density. A low speed heated jet is used to validate the measurement of temperature fluctuations and an acoustically excited nozzle flow is studied to validate velocity fluctuation measurements. Power spectral density calculations of the property fluctuations, as well as mean and fluctuating quantities are presented. Temperature fluctuation results are compared with constant current anemometry measurements and velocity fluctuation results are compared with constant temperature anemometry measurements at the same locations.

  2. Rayleigh Scattering Diagnostic for Measurement of Temperature, Velocity, and Density Fluctuation Spectra

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.; Sung, Chih-Jen; Panda, Jayanta

    2006-01-01

    A molecular Rayleigh scattering technique is developed to measure dynamic gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 10 kHz. A high power CW laser beam is focused at a point in a heated air jet plume and Rayleigh scattered light is collected and spectrally resolved. The spectrum of the light, which contains information about the temperature, velocity, and density of the flow, is analyzed using a Fabry-Perot interferometer. The circular interference fringe pattern is divided into four concentric regions and sampled at 1 and 10 kHz using photon counting electronics. Monitoring the relative change in intensity within each region allows for measurement of gas temperature and velocity. Independently monitoring the total scattered light intensity provides a measure of gas density. Power spectral density calculations of temperature, velocity, and density fluctuations, as well as mean and fluctuating quantities are demonstrated for various radial locations in the jet flow at a fixed axial distance from the jet exit plane. Results are compared with constant current anemometry and pitot probe measurements at the same locations.

  3. Optical measurement of acoustic pressure amplitudes-at the sensitivity limits of Rayleigh scattering.

    PubMed

    Rausch, Anne; Fischer, André; Kings, Nancy; Bake, Friedrich; Roehle, Ingo

    2012-07-01

    Rayleigh scattering is a measurement technique applicable for the determination of density distributions in various technical or natural flows. The current sensitivity limits of the Rayleigh scattering technique were investigated experimentally. It is shown that it is possible to measure density oscillations caused by acoustic pressure oscillations noninvasively and directly. Acoustical standing waves in a rectangular duct were investigated using Rayleigh scattering and compared to microphone measurements. The comparison showed a sensitivity of the Rayleigh scattering technique of 75 Pa (7·10(-4) kg/m(3)) and a precision of 14 Pa (1·10(-4) kg/m(3)). Therefore, it was also shown that Rayleigh scattering is applicable for acoustic measurements. PMID:22743495

  4. Characterization of a Combined CARS and Interferometric Rayleigh Scattering System

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah A.; Bivolaru, Daniel; Danehy, Paul M.; Weikl, M. C.; Beyrau, F.; Seeger, T.; Cutler, Andrew D.

    2007-01-01

    This paper describes the characterization of a combined Coherent anti-Stokes Raman Spectroscopy and Interferometric Rayleigh Scattering (CARS-IRS) system by reporting the accuracy and precision of the measurements of temperature, species mole fraction of N2, O2, and H2, and two-components of velocity. A near-adiabatic H2-air Hencken burner flame was used to provide known properties for measurements made with the system. The measurement system is also demonstrated in a small-scale Mach 1.6 H2-air combustion-heated supersonic jet with a co-flow of H2. The system is found to have a precision that is sufficient to resolve fluctuations of flow properties in the mixing layer of the jet.

  5. Coherent Rayleigh-Brillouin scattering as a flow diagnostic technique

    SciTech Connect

    Graul, J. S.; Lilly, T. C.

    2014-12-09

    Broadband coherent Rayleigh-Brillouin scattering (CRBS) was used to measure translational gas temperatures for nitrogen at the ambient pressure of 0.8 atm using a purpose-built Fabry-Perot etalon spectrometer. Temperatures derived from the CRBS spectral analysis were compared with experimentally-measured temperatures, and were found to be, on average, within 2% of the experimentally-measured value. Axial flow velocities from a double jet at a pressure ratio of 0.38 were also measured by looking at the Doppler shift of the CRBS line shape. With recent developments in chirped laser technology and the capacity of CRBS to simultaneously provide thermodynamic and bulk flow information, the CRBS line shape acquisition and analysis technique presented here may allow for future time-resolved, characterization of aerospace flows.

  6. Dynamic Measurement of Temperature, Velocity, and Density in Hot Jets Using Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.

    2009-01-01

    A molecular Rayleigh scattering technique is utilized to measure gas temperature, velocity, and density in unseeded gas flows at sampling rates up to 10 kHz, providing fluctuation information up to 5 kHz based on the Nyquist theorem. A high-power continuous-wave laser beam is focused at a point in an air flow field and Rayleigh scattered light is collected and fiber-optically transmitted to a Fabry-Perot interferometer for spectral analysis. Photomultiplier tubes operated in the photon counting mode allow high-frequency sampling of the total signal level and the circular interference pattern to provide dynamic density, temperature, and velocity measurements. Mean and root mean square velocity, temperature, and density, as well as power spectral density calculations, are presented for measurements in a hydrogen-combustor heated jet facility with a 50.8-mm diameter nozzle at NASA John H. Glenn Research Center at Lewis Field. The Rayleigh measurements are compared with particle image velocimetry data and computational fluid dynamics predictions. This technique is aimed at aeronautics research related to identifying noise sources in free jets, as well as applications in supersonic and hypersonic flows where measurement of flow properties, including mass flux, is required in the presence of shocks and ionization occurrence.

  7. Dynamic Measurement of Temperature, Velocity, and Density in Hot Jets Using Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.

    2008-01-01

    A molecular Rayleigh scattering technique was utilized to measure time-resolved gas temperature, velocity, and density in unseeded gas flows at sampling rates up to 10 kHz. A high power continuous-wave (cw) laser beam was focused at a point in an air flow field and Rayleigh scattered light was collected and fiber-optically transmitted to a Fabry-Perot interferometer for spectral analysis. Photomultipler tubes operated in the photon counting mode allowed high frequency sampling of the total signal level and the circular interference pattern to provide time-resolved density, temperature, and velocity measurements. Mean and rms velocity and temperature, as well as power spectral density calculations, are presented for measurements in a hydrogen-combustor heated jet facility with a 50.8-mm diameter nozzle at the NASA Glenn Research Center (GRC). The Rayleigh measurements are compared with particle image velocimetry data and CFD predictions. This technique is aimed at aeronautics research related to identifying noise sources in free jets, as well as applications in supersonic and hypersonic flows where measurement of flow properties, including mass flux, is required in the presence of shocks and ionization occurrence.

  8. Laser light scattering review

    NASA Astrophysics Data System (ADS)

    Schaetzel, Klaus

    1989-08-01

    Since the development of laser light sources and fast digital electronics for signal processing, the classical discipline of light scattering on liquid systems experienced a strong revival plus an enormous expansion, mainly due to new dynamic light scattering techniques. While a large number of liquid systems can be investigated, ranging from pure liquids to multicomponent microemulsions, this review is largely restricted to applications on Brownian particles, typically in the submicron range. Static light scattering, the careful recording of the angular dependence of scattered light, is a valuable tool for the analysis of particle size and shape, or of their spatial ordering due to mutual interactions. Dynamic techniques, most notably photon correlation spectroscopy, give direct access to particle motion. This may be Brownian motion, which allows the determination of particle size, or some collective motion, e.g., electrophoresis, which yields particle mobility data. Suitable optical systems as well as the necessary data processing schemes are presented in some detail. Special attention is devoted to topics of current interest, like correlation over very large lag time ranges or multiple scattering.

  9. Laser light scattering review

    NASA Technical Reports Server (NTRS)

    Schaetzel, Klaus

    1989-01-01

    Since the development of laser light sources and fast digital electronics for signal processing, the classical discipline of light scattering on liquid systems experienced a strong revival plus an enormous expansion, mainly due to new dynamic light scattering techniques. While a large number of liquid systems can be investigated, ranging from pure liquids to multicomponent microemulsions, this review is largely restricted to applications on Brownian particles, typically in the submicron range. Static light scattering, the careful recording of the angular dependence of scattered light, is a valuable tool for the analysis of particle size and shape, or of their spatial ordering due to mutual interactions. Dynamic techniques, most notably photon correlation spectroscopy, give direct access to particle motion. This may be Brownian motion, which allows the determination of particle size, or some collective motion, e.g., electrophoresis, which yields particle mobility data. Suitable optical systems as well as the necessary data processing schemes are presented in some detail. Special attention is devoted to topics of current interest, like correlation over very large lag time ranges or multiple scattering.

  10. Beyond the classical Rayleigh limit with twisted light.

    PubMed

    Tong, Zhisong; Korotkova, Olga

    2012-07-01

    It is shown that twisted stochastic light can serve as illumination that may produce images with a resolution overcoming the Rayleigh limit by an order of magnitude. This finding is illustrated for an isoplanatic axially symmetric system with low angular aperture and twisted scalar Gaussian Schell-model illumination.

  11. Time-Average Measurement of Velocity, Density, Temperature, and Turbulence Using Molecular Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Seasholtz, Richard G.; Elam, Krisie A.; Panda, Jayanta

    2004-01-01

    Measurement of time-averaged velocity, density, temperature, and turbulence in gas flows using a nonintrusive, point-wise measurement technique based on molecular Rayleigh scattering is discussed. Subsonic and supersonic flows in a 25.4-mm diameter free jet facility were studied. The developed instrumentation utilizes a Fabry-Perot interferometer to spectrally resolve molecularly scattered light from a laser beam passed through a gas flow. The spectrum of the scattered light contains information about velocity, density, and temperature of the gas. The technique uses a slow scan, low noise 16-bit depth CCD camera to record images of the fringes formed by Rayleigh scattered light passing through the interferometer. A kinetic theory model of the Rayleigh scattered light is used in a nonlinear least squares fitting routine to estimate the unknown parameters from the fringe images. The ability to extract turbulence information from the fringe image data proved to be a challenge since the fringe is broadened by not only turbulence, but also thermal fluctuations and aperture effects from collecting light over a range of scattering angles. Figure 1 illustrates broadening of a Rayleigh spectrum typical of flow conditions observed in this work due to aperture effects and turbulence for a scattering angle, chi(sub s), of 90 degrees, f/3.67 collection optics, mean flow velocity, u(sub k), of 300 m/s, and turbulent velocity fluctuations, sigma (sub uk), of 55 m/s. The greatest difficulty in processing the image data was decoupling the thermal and turbulence broadening in the spectrum. To aid in this endeavor, it was necessary to seed the ambient air with smoke and dust particulates; taking advantage of the turbulence broadening in the Mie scattering component of the spectrum of the collected light (not shown in the figure). The primary jet flow was not seeded due to the difficulty of the task. For measurement points lacking particles, velocity, density, and temperature

  12. Size Estimation and Time Evolution of Large Size Rare Gas Clusters by Rayleigh Scattering Techniques

    NASA Astrophysics Data System (ADS)

    Liu, Bing-Chen; Zhu, Pin-Pin; Li, Zhao-Hui; Ni, Guo-Quan; Xu, Zhi-Zhan

    2002-05-01

    Large rare gas clusters Arn, Krn and Xen were produced at room temperature in the process of supersonic adiabatic expansion. The cluster size is examined by a Rayleigh scattering experiment. Power variations of the average cluster size 0256-307X/19/5/316/art16 with the gas backing pressure P0 give size scaling as 0256-307X/19/5/316/art16 ∝P02.0, resulting in the largest cluster sizes which are estimated in the present work to be about 1.5×104, 2.6×104 and 4.0×104 atoms (the corresponding diameters of the cluster spheres are about 9, 13 and 17 nm) for Ar, Kr and Xe, respectively. A time resolving Rayleigh scattering experiment was conducted to investigate the time evolution of cluster formation and decay processes. A surprising two-plateau structure of the time evolution characteristic of cluster formation and decay processes of Kr and Xe clusters was revealed as compared with a ``normal'' single structure for the case of Ar gas. In the second plateau, the intensity of the scattered light is enhanced greatly, by even as much as 62 times, over that in the first plateau, indicating a significant increase in cluster size. This finding supports the importance of nuclei in the gas condensation process and may be helpful for further insight into the phenomenon of clustering.

  13. Scattering Of Light Nuclei

    SciTech Connect

    Quaglioni, S; Navratil, P; Roth, R

    2009-12-15

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.

  14. Fluorescence and Light Scattering

    ERIC Educational Resources Information Center

    Clarke, Ronald J.; Oprysa, Anna

    2004-01-01

    The aim of the mentioned experiment is to aid students in developing tactics for distinguishing between signals originating from fluorescence and light scattering. Also, the experiment provides students with a deeper understanding of the physicochemical bases of each phenomenon and shows that the techniques are actually related.

  15. The application of laser Rayleigh scattering to a reciprocating model engine

    SciTech Connect

    Arcoumains, C.; Green, H.G.; Whitelaw, J.H.

    1984-02-01

    The Rayleigh light scattering technique has been used to quantify the mean and fluctuating concentration of a passive scalar used to simulate fuel injection in a reciprocating, two-stroke model engine motored at 200 rpm in the absence of compression. The transient concentration field, which results from injection of Freon-12 vapour through the centre of an axisymmetrically located permanently open valve, has been investigated for injection timings of 40 deg. before and at top-dead-centre as a function of spatial position and crank angle. The purpose-built Rayleigh system, with gated digital data acquisition and software dust particle filtering, was first evaluated in a Freon-12 free jet by comparing results to those obtained with a sampling probe. At low concentration fluctuations and independent of particle density the agreement between the two methods is excellent but at high concentration fluctuations and particle density the Rayleigh system overestimates the Freon-12 mole fraction by up to about 10% for reasons which are discussed. The results obtained in the model engine indicate that the Freon-12 concentration field expressed in terms of ensemble-averaged mole fractions and rms of concentration fluctuations, is dominated by the high momentum transient jet which, in the near field, exhibits similar trends to the steady jet. Impingement of the jet onto the flat piston improves mixing giving rise to nearly uniform concentration fluctuations of about 10%.

  16. Time-Average Molecular Rayleigh Scattering Technique for Measurement of Velocity, Denisty, Temperature, and Turbulence Intensity in High Speed Nozzle Flows

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Seasholtz, Richard G.; Elam, Kristie A.; Panda, Jayanta

    2004-01-01

    A molecular Rayleigh scattering based flow diagnostic is developed to measure time average velocity, density, temperature, and turbulence intensity in a 25.4-mm diameter nozzle free jet facility. The spectrum of the Rayleigh scattered light is analyzed using a Fabry-Perot interferometer operated in the static imaging mode. The resulting fringe pattern containing spectral information of the scattered light is recorded using a low noise CCD camera. Nonlinear least squares analysis of the fringe pattern using a kinetic theory model of the Rayleigh scattered light provides estimates of density, velocity, temperature, and turbulence intensity of the gas flow. Resulting flow parameter estimates are presented for an axial scan of subsonic flow at Mach 0.95 for comparison with previously acquired pitot tube data, and axial scans of supersonic flow in an underexpanded screeching jet. The issues related to obtaining accurate turbulence intensity measurements using this technique are discussed.

  17. Rayleigh scatter based order of magnitude increase in distributed temperature and strain sensing by simple UV exposure of optical fibre.

    PubMed

    Loranger, Sébastien; Gagné, Mathieu; Lambin-Iezzi, Victor; Kashyap, Raman

    2015-06-16

    We present a technique to improve signal strength, and therefore sensitivity in distributed temperature and strain sensing (DTSS) using Frequency domain Rayleigh scatter. A simple UV exposure of a hydrogen loaded standard SMF-28 fibre core is shown to enhance the Rayleigh back-scattered light dramatically by ten-fold, independent of the presence of a Bragg grating, and is therefore created by the UV exposure alone. This increase in Rayleigh back-scatter allows an order-of-magnitude increase in temperature and strain resolution for DTSS compared to un-exposed SMF-28 fibre used as a sensing element. This enhancement in sensitivity is effective for cm range or more sensor gauge length, below which is the theoretical cross-correlation limit. The detection of a 20 mK temperature rise with a spatial resolution of 2 cm is demonstrated. This gain in sensitivity for SMF-28 is compared with a high Ge doped photosensitive fibre with a characteristically high NA. For the latter, the UV enhancement is also present although of lower amplitude, and enables an even lower noise level for sensing, due to the fibre's intrinsically higher Rayleigh scatter signal.

  18. Rayleigh scatter based order of magnitude increase in distributed temperature and strain sensing by simple UV exposure of optical fibre

    PubMed Central

    Loranger, Sébastien; Gagné, Mathieu; Lambin-Iezzi, Victor; Kashyap, Raman

    2015-01-01

    We present a technique to improve signal strength, and therefore sensitivity in distributed temperature and strain sensing (DTSS) using Frequency domain Rayleigh scatter. A simple UV exposure of a hydrogen loaded standard SMF-28 fibre core is shown to enhance the Rayleigh back-scattered light dramatically by ten-fold, independent of the presence of a Bragg grating, and is therefore created by the UV exposure alone. This increase in Rayleigh back-scatter allows an order-of-magnitude increase in temperature and strain resolution for DTSS compared to un-exposed SMF-28 fibre used as a sensing element. This enhancement in sensitivity is effective for cm range or more sensor gauge length, below which is the theoretical cross-correlation limit. The detection of a 20 mK temperature rise with a spatial resolution of 2 cm is demonstrated. This gain in sensitivity for SMF-28 is compared with a high Ge doped photosensitive fibre with a characteristically high NA. For the latter, the UV enhancement is also present although of lower amplitude, and enables an even lower noise level for sensing, due to the fibre’s intrinsically higher Rayleigh scatter signal. PMID:26077365

  19. Rayleigh scatter based order of magnitude increase in distributed temperature and strain sensing by simple UV exposure of optical fibre

    NASA Astrophysics Data System (ADS)

    Loranger, Sébastien; Gagné, Mathieu; Lambin-Iezzi, Victor; Kashyap, Raman

    2015-06-01

    We present a technique to improve signal strength, and therefore sensitivity in distributed temperature and strain sensing (DTSS) using Frequency domain Rayleigh scatter. A simple UV exposure of a hydrogen loaded standard SMF-28 fibre core is shown to enhance the Rayleigh back-scattered light dramatically by ten-fold, independent of the presence of a Bragg grating, and is therefore created by the UV exposure alone. This increase in Rayleigh back-scatter allows an order-of-magnitude increase in temperature and strain resolution for DTSS compared to un-exposed SMF-28 fibre used as a sensing element. This enhancement in sensitivity is effective for cm range or more sensor gauge length, below which is the theoretical cross-correlation limit. The detection of a 20 mK temperature rise with a spatial resolution of 2 cm is demonstrated. This gain in sensitivity for SMF-28 is compared with a high Ge doped photosensitive fibre with a characteristically high NA. For the latter, the UV enhancement is also present although of lower amplitude, and enables an even lower noise level for sensing, due to the fibre’s intrinsically higher Rayleigh scatter signal.

  20. Ring effect studies: Rayleigh scattering, including molecular parameters for rotational Raman scattering, and the Fraunhofer spectrum.

    PubMed

    Chance, K V; Spurr, R J

    1997-07-20

    Improved parameters for the description of Rayleigh scattering in air and for the detailed rotational Raman scattering component for scattering by O(2) and N(2) are presented for the wavelength range 200-1000 nm. These parameters enable more accurate calculations to be made of bulk molecular scattering and of the Ring effect for a variety of atmospheric radiative transfer and constituent retrieval applications. A solar reference spectrum with accurate absolute vacuum wavelength calibration, suitable for convolution with the rotational Raman spectrum for Ring effect calculations, has been produced at 0.01-nm resolution from several sources. It is convolved with the rotational Raman spectra of O(2) and N(2) to produce an atmospheric Ring effect source spectrum.

  1. Matrix operator theory of radiative transfer. 1: rayleigh scattering.

    PubMed

    Plass, G N; Kattawar, G W; Catchings, F E

    1973-02-01

    An entirely rigorous method for the solution of the equations for radiative transfer based on the matrix operator theory is reviewed. The advantages of the present method are: (1) all orders of the reflection and transmission matrices are calculated at once; (2) layers of any thickness may be combined, so that a realistic model of the atmosphere can be developed from any arbitrary number of layers, each with different properties and thicknesses; (3) calculations can readily be made for large optical depths and with highly anisotropic phase functions; (4) results are obtained for any desired value of the surface albedo including the value unity and for a large number of polar and azimuthal angles including the polar angle theta = 0 degrees ; (5) all fundamental equations can be interpreted immediately in terms of the physical interactions appropriate to the problem; (6) both upward and downward radiance can be calculated at interior points from relatively simple expressions. Both the general theory and its history together with the method of calculation are discussed. As a first example of the method numerous curves are given for both the reflected and transmitted radiance for Rayleigh scattering from a homogeneous layer for a range of optical thicknesses from 0.0019 to 4096, surface albedo A = 0, 0.2, and 1, and cosine of solar zenith angle micro = 1, 0.5397, and 0.1882. It is shown that the matrix operator approach contains the doubling method as a special case.

  2. Imaging of Passive Scalar Fields by Filtered Rayleigh Scattering

    NASA Astrophysics Data System (ADS)

    Kearney, Sean; Grasser, Thomas; Beresh, Steven; Schefer, Robert

    2002-11-01

    Filtered Rayleigh Scattering (FRS) is a molecular-filter-based, laser-diagnostic approach for multiparameter flowfield imaging that has been gaining popularity over the past 5-10 years [1]. Advantages of FRS for noninvasive gas-phase imaging include: (1) elimination of particle or chemical seeding requirements, (2) increased optical noise rejection allowing imaging close to walls and in "dirty" laboratory environments, (3) imaging of multiple flowfield parameters with a single diagnostic. In this work, the construction and performance of a FRS optical system for passive scalar imaging at Sandia National Laboratories is presented. Data were obtained in an open lab where no special precautions for the elimination of room particulate were made. Results from nonreacting jets and from a premixed flame are shown. Temperature imaging in a nonreacting, steady calibration jet reveals the precision of the time-averaged FRS thermometry results to be ±20 K, or 4of the characteristic temperature difference, while the single-laser-pulse precision is degraded to approximately ±40-50 K. These results are adequate for combustion thermometry purposes. Relative to the jet temperature measurements, species concentration imaging of a buoyant helium jet displays increased signal dynamic range and further improved precision. Reacting flow measurements from the combustion-product region of a methane-air Hencken-type premixed flame are also presented and a comparison of FRS and coherent anti-Stokes Raman scattering (CARS) experiments to calculated adiabatic-equilibrium product temperatures is made which validates the suitability of our FRS instrument for combustion temperature imaging. [1]G.S. Elliott, N. Glumac, and C.D. Carter, Meas. Sci. Tech., 12, 452, 2001.

  3. Spatially and Temporally-Resolved Multi-Parameter Interferometric Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Cutler, Andrew D.; Danehy, Paul M.

    2011-01-01

    A novel approach to simultaneously measure the translational temperature, bulk velocity, and density in gases by collecting, referencing, and analyzing nanosecond time-scale Rayleigh scattered light from molecules is described. A narrow-band pulsed laser source is used to probe two largely separated measurement locations, one of which is used for reference. The elastically scattered photons containing information from both measurement locations are collected at the same time and analyzed spectrally using a planar Fabry - Perot interferometer. A practical means of referencing the measurement of velocity using the laser frequency, and the density and temperature using the information from the reference measurement location maintained at constant properties is described. To demonstrate the technique single-shot spectra of elastic scattered light are obtained in a near zero velocity H2-air Hencken burner flame and simultaneously in an N2-filled gas cell. A simplified Gaussian distribution model to the scattered light spectra is used to obtain the flame properties. Corrections to this model are applied at lower gas temperatures when the simplified Gaussian approximation is no longer suitable. The near-zero measured velocity as a function of the measured flame temperature, and a comparison of the measured flame density and temperature with the perfect gas law are presented.

  4. The application of laser Rayleigh scattering to gas density measurements in hypersonic helium flows

    NASA Technical Reports Server (NTRS)

    Hoppe, J. C.; Honaker, W. C.

    1979-01-01

    Measurements of the mean static free-stream gas density have been made in two Langley Research Center helium facilities, the 3-inch leg of the high-Reynolds-number helium complex and the 22-inch hypersonic helium tunnel. Rayleigh scattering of a CW argon ion laser beam at 514.5 nm provided the basic physical mechanism. The behavior of the scattered signal was linear, confirmed by a preliminary laboratory study. That study also revealed the need to introduce baffles to reduce stray light. A relatively simple optical system and associated photon-counting electronics were utilized to obtain data for densities from 10 to the 23rd to 10 to the 25th per cu m. The major purpose, to confirm the applicability of this technique in the hypersonic helium flow, was accomplished.

  5. Investigation of Condensation/Clustering Effects on Rayleigh Scattering Measurements in a Hypersonic Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Tyler, Charles

    1996-01-01

    Rayleigh scattering, a nonintrusive measurement technique for the measurement of density in a hypersonic wind tunnel, is under investigation at Wright Laboratory's Mach 6 wind tunnel. Several adverse effects, i.e., extraneous scatter off walls and windows, hinder Rayleigh scattering measurements. Condensation and clustering of flow constituents also present formidable obstacles. Overcoming some of these difficulties, measurements have been achieved while the Mach 6 test section was pumped down to a vacuum, as well as for actual tunnel operation for various stagnation pressures at fixed stagnation temperatures. Stagnation pressures ranged from 0.69 MPa to 6.9 MPa at fixed stagnation temperatures of 511, 556, and 611 K. Rayleigh scatter results show signal levels much higher than expected for molecular scattering in the wind tunnel. Even with higher than expected signals, scattering measurements have been made in the flowfield of an 8-degree half-angle blunt nose cone with a nose radius of 1.5 cm.

  6. Contribution of Rayleigh scattering on Brillouin comb line generation in Raman fiber laser.

    PubMed

    Zamzuri, Abdul Kadir; Al-Mansoori, Mohammed Hayder; Samsuri, Norhakimah Md; Mahdi, Mohd Adzir

    2010-06-20

    We demonstrate the generation of multiple Brillouin Stokes lines generation assisted by Rayleigh scattering in Raman fiber laser. The linear cavity is utilized to take advantage of the Rayleigh scattering effect, and it also produces two strong spectral peaks at 1555 and 1565nm. Under a strong pumping condition, the Rayleigh backscatters contribute to the oscillation efficiency, which increases the Brillouin Stokes lines intensity between these two wavelength ranges. The multiple Stokes lines get stronger by suppressing the buildup of free-running longitudinal modes in the laser structure.

  7. Investigation of differential diffusion in turbulent jet flows using planar laser Rayleigh scattering

    SciTech Connect

    Dibble, Robert W.; Long, Marshall B.

    2005-12-01

    A series of laser Rayleigh-scattering experiments has been performed to investigate the effects of differential molecular diffusion in turbulent nonreacting jet flows. A turbulent jet of a mixture of Freon and H{sub 2} exiting into coflowing air was studied at various Reynolds numbers. In laminar flow, Rayleigh scattering clearly showed H{sub 2} diffusing ahead of Freon. In turbulent flow, the instantaneous Rayleigh images showed differential diffusion at the many interfaces between jet fluid and entrained air. Yet, ensemble averages of instantaneous images showed no average diffusion of H{sub 2} ahead of Freon.

  8. Superradiant rayleigh scattering and collective atomic recoil lasing in a ring cavity.

    PubMed

    Slama, S; Bux, S; Krenz, G; Zimmermann, C; Courteille, Ph W

    2007-02-01

    Collective interaction of light with an atomic gas can give rise to superradiant instabilities. We experimentally study the sudden buildup of a reverse light field in a laser-driven high-finesse ring cavity filled with ultracold thermal or Bose-Einstein condensed atoms. While superradiant Rayleigh scattering from atomic clouds is normally observed only at very low temperatures (i.e., well below 1 microK), the presence of the ring cavity enhances cooperativity and allows for superradiance with thermal clouds as hot as several 10 microK. A characterization of the superradiance at various temperatures and cooperativity parameters allows us to link it to the collective atomic recoil laser.

  9. Use of two profilers during MCTEX for unambiguous identification of Bragg scattering and Rayleigh scattering

    SciTech Connect

    Gage, K.S.; Williams, C.R.; Ecklund, W.L.; Johnston, P.E.

    1999-11-01

    A 2835-MHz (10.6-cm wavelength) profiler and a 920-MHz (32.6-cm wavelength) profiler were collocated by the NOAA Aeronomy Laboratory at Garden Point, Australia, in the Tiwi Islands during the Maritime Continent Thunderstorm Experiment (MCTEX) field campaign in November and December 1995. The two profilers were directed vertically and observed vertical velocities in the clear atmosphere and hydrometeor fall velocities in deep precipitating cloud systems. In the absence of Rayleigh scatterers, the profilers obtain backscattering from the refractive index irregularities created from atmospheric turbulence acting upon refractive index gradients. This kind of scattering is commonly referred to as Bragg scattering and is only weakly dependent on the radar wavelength provided the radar half-wavelength lies within the inertial subrange of homogeneous, isotropic turbulence. In the presence of hydrometeors the profilers observe Rayleigh backscattering from hydrometeors much as weather radars do and this backscatter is very dependent upon radar wavelength, strongly favoring the shorter wavelength profiler resulting in a 20-dB enhancement of the ability of the 2835-MHz profiler to observe hydrometeors. This paper presents observations of equivalent reflectivity, Doppler velocity, and spectral width made by collocated profilers during MCTEX. Differential reflectivity is used to diagnose the type of echo observed by the profilers in the spectral moment data.

  10. Diode Laser Velocity Measurements by Modulated Filtered Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mach, J. J.; Varghese, P. L.; Jagodzinski, J. J.

    1999-01-01

    The ability of solid-state lasers to be tuned in operating frequency at MHz rates by input current modulation, while maintaining a relatively narrow line-width, has made them useful for spectroscopic measurements. Their other advantages include low cost, reliability, durability, compact size, and modest power requirements, making them a good choice for a laser source in micro-gravity experiments in drop-towers and in flight. For their size, they are also very bright. In a filtered Rayleigh scattering (FRS) experiment, a diode laser can be used to scan across an atomic or molecular absorption line, generating large changes in transmission at the resonances for very small changes in frequency. The hyperfine structure components of atomic lines of alkali metal vapors are closely spaced and very strong, which makes such atomic filters excellent candidates for sensitive Doppler shift detection and therefore for high-resolution velocimetry. In the work we describe here we use a Rubidium vapor filter, and work with the strong D(sub 2) transitions at 780 nm that are conveniently accessed by near infrared diode lasers. The low power output of infrared laser diodes is their primary drawback relative to other laser systems commonly used for velocimetry. However, the capability to modulate the laser frequency rapidly and continuously helps mitigate this. Using modulation spectroscopy and a heterodyne detection scheme with a lock-in amplifier, one can extract sub-microvolt signals occurring at a specific frequency from a background that is orders of magnitude stronger. The diode laser modulation is simply achieved by adding a small current modulation to the laser bias current. It may also be swept repetitively in wavelength using an additional lower frequency current ramp.

  11. Light Scattering by Spheroids

    NASA Astrophysics Data System (ADS)

    Xie, Ya-Ming; Ji, Xia

    Nowadays, with the development of technology, particles with size at nanoscale have been synthesized in experiments. It is noticed that anisotropy is an unavoidable problem in the production of nanospheres. Besides, nonspherical nanoparticles have also been extensively used in experiments. Comparing with spherical model, spheroidal model can give a better description for the characteristics of nonspherical particles. Thus the study of analytical solution for light scattering by spheroidal particles has practical implications. By expanding incident, scattered, and transmitted electromagnetic fields in terms of appropriate vector spheroidal wave functions, an analytic solution is obtained to the problem of light scattering by spheroids. Unknown field expansion coefficients can be determined with the combination of boundary conditions and rotational-translational addition theorems for vector spheroidal wave functions. Based on the theoretical derivation, a Fortran code has been developed to calculate the extinction cross section and field distribution, whose results agree well with those obtain by FDTD simulation. This research is supported by the National Natural Science Foundation of China No. 91230203.

  12. Critical fluid light scattering

    NASA Technical Reports Server (NTRS)

    Gammon, Robert W.

    1988-01-01

    The objective is to measure the decay rates of critical density fluctuations in a simple fluid (xenon) very near its liquid-vapor critical point using laser light scattering and photon correlation spectroscopy. Such experiments were severely limited on Earth by the presence of gravity which causes large density gradients in the sample when the compressibility diverges approaching the critical point. The goal is to measure fluctuation decay rates at least two decades closer to the critical point than is possible on earth, with a resolution of 3 microK. This will require loading the sample to 0.1 percent of the critical density and taking data as close as 100 microK to the critical temperature. The minimum mission time of 100 hours will allow a complete range of temperature points to be covered, limited by the thermal response of the sample. Other technical problems have to be addressed such as multiple scattering and the effect of wetting layers. The experiment entails measurement of the scattering intensity fluctuation decay rate at two angles for each temperature and simultaneously recording the scattering intensities and sample turbidity (from the transmission). The analyzed intensity and turbidity data gives the correlation length at each temperature and locates the critical temperature. The fluctuation decay rate data from these measurements will provide a severe test of the generalized hydrodynamic theories of transport coefficients in the critical regions. When compared to equivalent data from binary liquid critical mixtures they will test the universality of critical dynamics.

  13. Stimulated Rayleigh-Bragg scattering in two-photon absorbing media

    SciTech Connect

    He, Guang S.; Lu Changgui; Zheng Qingdong; Prasad, Paras N.; Zerom, Petros; Boyd, Robert W.; Samoc, Marek

    2005-06-15

    The origin and mechanism of backward stimulated Rayleigh scattering in two-photon absorbing media are studied theoretically and experimentally. This type of stimulated scattering has the unusual features of no frequency shift and low pump threshold requirement compared to all other known stimulated scattering effects. This frequency-unshifted stimulated Rayleigh scattering effect can be well explained by a two-photon-excitation-enhanced Bragg grating reflection model. The reflection of the forward pump beam from this stationary Bragg grating may substantially enhance the backward Rayleigh scattering beam, providing a positive feedback mechanism without causing any frequency shift. A two-counterpropagating-beam-formed grating experiment in a two-photon absorbing dye solution is conducted. The measured dynamic behavior of Bragg grating formation and reflectivity properties are basically consistent with the predictions from the proposed model.

  14. Dynamic light scattering microscopy

    NASA Astrophysics Data System (ADS)

    Dzakpasu, Rhonda

    An optical microscope technique, dynamic light scattering microscopy (DLSM) that images dynamically scattered light fluctuation decay rates is introduced. Using physical optics we show theoretically that within the optical resolution of the microscope, relative motions between scattering centers are sufficient to produce significant phase variations resulting in interference intensity fluctuations in the image plane. The time scale for these intensity fluctuations is predicted. The spatial coherence distance defining the average distance between constructive and destructive interference in the image plane is calculated and compared with the pixel size. We experimentally tested DLSM on polystyrene latex nanospheres and living macrophage cells. In order to record these rapid fluctuations, on a slow progressive scan CCD camera, we used a thin laser line of illumination on the sample such that only a single column of pixels in the CCD camera is illuminated. This allowed the use of the rate of the column-by-column readout transfer process as the acquisition rate of the camera. This manipulation increased the data acquisition rate by at least an order of magnitude in comparison to conventional CCD cameras rates defined by frames/s. Analysis of the observed fluctuations provides information regarding the rates of motion of the scattering centers. These rates, acquired from each position on the sample are used to create a spatial map of the fluctuation decay rates. Our experiments show that with this technique, we are able to achieve a good signal-to-noise ratio and can monitor fast intensity fluctuations, on the order of milliseconds. DLSM appears to provide dynamic information about fast motions within cells at a sub-optical resolution scale and provides a new kind of spatial contrast.

  15. Determination of surface normal temperature gradients using thermographic phosphors and filtered Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Brübach, J.; Zetterberg, J.; Omrane, A.; Li, Z. S.; Aldén, M.; Dreizler, A.

    2006-09-01

    Wall temperature as well as the temperature distribution within or close-by the boundary layer of an electrically heated axisymmetric jet impinging on a flat plate were monitored to deduce wall-normal temperature gradients. The radial surface temperature profile of the plate was determined by coating it with thermographic phosphors (TPs), materials whose phosphorescence decay time is dependent on their temperature. The TP was excited electronically by a frequency-tripled Nd:YAG laser (355 nm) and the temporal decay of the phosphorescence intensity was measured zero-dimensionally by a photomultiplier tube. In this case the 659-nm emission line of Mg3F2GeO4:Mn was monitored. The non-intrusive measurement of gas temperatures near the surface was performed two-dimensionally by filtered Rayleigh scattering (FRS). A tunable frequency-tripled single-longitudinal-mode alexandrite laser beam at 254 nm was formed into a light sheet pointing parallel to the surface. The scattered light was imaged through a very narrow linewidth atomic mercury filter onto an intensified charged coupled device (ICCD). The elastic stray light from surfaces was strongly suppressed, whereas Doppler-broadened light was detected. Thermographic phosphors proved to be reliable for the measurement of surface temperatures. Dependent on the specific experimental conditions, problems appeared with signals interfering with the FRS radiation close-by the surface. Results and challenges of this approach are discussed.

  16. Feasibility of Rayleigh Scattering Flow Diagnostics in the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Herring, Gregory C.; Lee, Joseph W.; Goad, William K.

    2015-01-01

    Laser-based Rayleigh light scattering (RLS) was performed in the National Transonic Facility (NTF) at NASA Langley Research Center. The goal was to determine if the free-stream flow undergoes clustering (early stage of condensation from gas to liquid) or remains in a pure diatomic molecular phase. Data indicate that clusters are not observable down to levels of 10% of the total light scatter for a variety of total pressures at one N2 cryogenic-mode total temperature (Tt = -50 F = 227 K) and one air-mode temperature (Tt = +130 F = 327 K). Thus RLS appears viable as a qualitative or quantitative diagnostic for flow density in NTF in the future. Particles are distinguished from optically unresolvable clusters because they are much larger and individually resolvable in the laser beam image with Mie scattering. The same RLS apparatus was also used, without modification, to visualize naturally occurring particles entrained in the flow for both cryogenic and air-modes. Estimates of the free-stream particle flux are presented, which may be important for interpretation of laminar-to-turbulent boundary-layer transition studies. 1

  17. Rayleigh-Brillouin scattering for high-pressure gas temperature measurements

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.

    1991-01-01

    An experiment was set up to evaluate the feasibility of using Rayleigh-Brillouin scattering as a diagnostic technique for measuring gas temperature in high pressure environments, such as the Space Shuttle Main Engine (SSME) Preburner. A high pressure furnace is used as the scattering chamber. Either nitrogen or hydrogen may be used. An argon ion laser beam is focused into the furnace. Light backscattering from the gas in the furnace is collected and analyzed with a 5-pass scanning Fabry-Perot interferometer and photon counting electronics. The multi-pass configuration provides the high frequency selectively needed to measure the Brillouin peaks in the presence of large amounts of spuriously scattered light at the laser frequency. Preliminary measurements were made at room temperature in nitrogen at pressures up to 2000 psia. The free spectral range of the interferometer and frequency separation of the Brillouin peaks are determined from measured spectra. Temperature measurements are then obtained using the simple continuum theory with low frequency values of specific heat ratio and shear viscosity. The measured temperatures are within 10 percent of the true value.

  18. A method of atmospheric density measurements during space shuttle entry using ultraviolet-laser Rayleigh scattering

    NASA Technical Reports Server (NTRS)

    Mckenzie, Robert L.

    1988-01-01

    An analytical study and its experimental verification are described which show the performance capabilities and the hardware requirements of a method for measuring atmospheric density along the Space Shuttle flightpath during entry. Using onboard instrumentation, the technique relies on Rayleigh scattering of light from a pulsed ArF excimer laser operating at a wavelength of 193 nm. The method is shown to be capable of providing density measurements with an uncertainty of less than 1 percent and with a spatial resolution along the flightpath of 1 km, over an altitude range from 50 to 90 km. Experimental verification of the signal linearity and the expected signal-to-noise ratios is demonstrated in a simulation facility at conditions that duplicate the signal levels of the flight environment.

  19. The development of a tunable, single-frequency ultraviolet laser source for UV filtered Rayleigh scattering

    NASA Technical Reports Server (NTRS)

    Finkelstein, N.; Gambogi, J.; Lempert, Walter R.; Miles, Richard B.; Rines, G. A.; Finch, A.; Schwarz, R. A.

    1995-01-01

    We present the development of a flexible, high power, narrow line width, tunable ultraviolet source for diagnostic application. By frequency tripling the output of a pulsed titanium-sapphire laser, we achieve broadly tunable (227-360 nm) ultraviolet light with high quality spatial and spectral resolution. We also present the characterization of a mercury vapor cell which provides a narrow band, sharp edge absorption filter at 253.7 nm. These two components form the basis for the extension of the Filtered Rayleigh Scattering technique into the ultraviolet. The UV-FRS system is comprised of four pieces: a single frequency, cw tunable Ti:Sapphire seeding source; a high-powered pulsed Ti:Sapphire oscillator; a third harmonic generator system; and an atomic mercury vapor filter. In this paper we discuss the development and characterization of each of these elements.

  20. Radial profile of micro-discharge temperature measured by ultraviolet laser Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Adams, Steven; Caplinger, James

    2012-10-01

    Air micro-discharge temperature profiles have been derived from measurements of elastic Rayleigh scatter of an ultraviolet laser pulse. Rayleigh scatter images have been recorded to measure spatially resolved translational temperatures along the radial dimension of the dc micro-discharge at various currents. The scatter image intensity along the laser beam axis is proportional to the background gas target density and thus, according to the ideal gas law, is inversely proportional to gas translational temperature. By measuring the scatter image with and without a discharge, the temperature was determined in one-dimension along the laser beam passing radially through the discharge. This laser scatter technique was compared to the technique of measuring rotational and vibrational temperatures by passive optical emission spectroscopy (OES) of the N2 second positive system. Results were generally consistent with the common assumption that Tvibrational>>Trotational=Ttranslational. Slight differences between Trotational and Ttranslational measured by laser scatter and OES techniques respectively are discussed.

  1. A High Performance Computing approach to model multiple Rayleigh scattering in the Earth atmosphere

    NASA Astrophysics Data System (ADS)

    Franssens, Ghislain; Dekemper, Emmanuel; Mateshivili, Nina; Vanhellemont, filip; fussen, didier; pieroux, didier

    2016-04-01

    The retrieval of atmospheric trace gases and aerosols in the Earth atmosphere from light scattering measurements typically involves an iterative inversion algorithm. A key part of this algorithm is its forward model, which takes care of calculating the amount of light that the remote sensing instrument will see, for any assumed atmosphere composition. The forward model is usually an atmospheric radiative transfer code. It is a serious challenge for a radiative transfer code to be, at the same time, sufficiently accurate and sufficiently fast, so that it can be included in the iterative retrieval loop of an operational service. An accurate code must be able to calculate multiple Rayleigh scattering (important in the UV and/or at lower altitudes) by the air in a spherical atmosphere. This is something that currently only a Monte Carlo algorithm can do. However, any Monte Carlo code is far too slow to be included in the retrieval loop, even if we make use of the currently available HPC power. We report some first results that were obtained by a new solution to this old problem. We first use a HPC cluster to tabulate multiple Rayleigh scattering in a standard Earth atmosphere, using a Monte Carlo code, as function of 6 parameters (albedo, view zenith angle, solar zenith angle, relative azimuth angle, altitude and wavelength). Then, a well chosen empirical function is fitted on the tabulated data. From this function, correction factors are derived and appropriately inserted in a fast single scattering algorithm, which so effectively becomes a multiple scattering algorithm. Since the evaluation of the empirical function is also very fast, we end up with a radiative transfer code that is both accurate and sufficiently fast for operational data production. Our conclusion is that commonly available and affordable HPC systems can still not directly solve the retrieval problem with sufficient accuracy in real time. However, the above described two step approach now becomes

  2. In situ nanoparticle diagnostics by multi-wavelength Rayleigh-Mie scattering ellipsometry

    NASA Astrophysics Data System (ADS)

    Gebauer, G.; Winter, J.

    2003-04-01

    We present and discuss the method of multiple-wavelength Rayleigh-Mie scattering ellipsometry for the in situ analysis of nanoparticles. It is applied to the problem of nanoparticles suspended in low-pressure plasmas. We discuss experimental results demonstrating that the size distribution and the complex refractive index can be determined with high accuracy and present a study on the in situ analysis of etching of melamine-formaldehyde nanoparticles suspended in an oxygen plasma. It is also shown that particles with a shell structure (core plus mantle) can be analysed by Rayleigh-Mie scattering ellipsometry. Rayleigh-Mie scattering ellipsometry is also applicable to in situ analysis of nanoparticles under high gas pressures and in liquids.

  3. Planar Rayleigh Scattering Results in Helium/Air Mixing Experiments in a Mach 6 Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Shirinzadeh, B.; Balla, R. Jeffrey; Hillard, M. E.; Anders, J. B.; Exton, R. J.; Waitz, I. A.

    1991-01-01

    Planar Rayleigh scattering measurements using an ArF-excimer laser have been performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach 6facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross sectional area (5 cm by 10 cm) of the flow field in the absence of clusters.

  4. Determination of the quantized topological magneto-electric effect in topological insulators from Rayleigh scattering

    PubMed Central

    Ge, Lixin; Zhan, Tianrong; Han, Dezhuan; Liu, Xiaohan; Zi, Jian

    2015-01-01

    Topological insulators (TIs) exhibit many exotic properties. In particular, a topological magneto-electric (TME) effect, quantized in units of the fine structure constant, exists in TIs. Here, we theoretically study the scattering properties of electromagnetic waves by TI circular cylinders particularly in the Rayleigh scattering limit. Compared with ordinary dielectric cylinders, the scattering by TI cylinders shows many unusual features due to the TME effect. Two proposals are suggested to determine the TME effect of TIs simply by measuring the electric-field components of scattered waves in the far field at one or two scattering angles. Our results could also offer a way to measure the fine structure constant. PMID:25609462

  5. Filtered Rayleigh scattering diagnostic for multi-parameter thermal-fluids measurements : LDRD final report.

    SciTech Connect

    Beresh, Steven Jay; Grasser, Thomas W.; Kearney, Sean Patrick; Schefer, Robert W.

    2004-01-01

    Simulation-based life-cycle-engineering and the ASCI program have resulted in models of unprecedented size and fidelity. The validation of these models requires high-resolution, multi-parameter diagnostics. Within the thermal-fluids disciplines, the need for detailed, high-fidelity measurements exceeds the limits of current engineering sciences capabilities and severely tests the state of the art. The focus of this LDRD is the development and application of filtered Rayleigh scattering (FRS) for high-resolution, nonintrusive measurement of gas-phase velocity and temperature. With FRS, the flow is laser-illuminated and Rayleigh scattering from naturally occurring sources is detected through a molecular filter. The filtered transmission may be interpreted to yield point or planar measurements of three-component velocities and/or thermodynamic state. Different experimental configurations may be employed to obtain compromises between spatial resolution, time resolution, and the quantity of simultaneously measured flow variables. In this report, we present the results of a three-year LDRD-funded effort to develop FRS combustion thermometry and Aerosciences velocity measurement systems. The working principles and details of our FRS opto-electronic system are presented in detail. For combustion thermometry we present 2-D, spatially correlated FRS results from nonsooting premixed and diffusion flames and from a sooting premixed flame. The FRS-measured temperatures are accurate to within {+-}50 K (3%) in a premixed CH4-air flame and within {+-}100 K for a vortex-strained diluted CH4-air diffusion flame where the FRS technique is severely tested by large variation in scattering cross section. In the diffusion flame work, FRS has been combined with Raman imaging of the CH4 fuel molecule to correct for the local light scattering properties of the combustion gases. To our knowledge, this is the first extension of FRS to nonpremixed combustion and the first use of joint FRS

  6. Molecular Rayleigh Scattering Diagnostic for Measurement of High Frequency Temperature Fluctuations

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.

    2005-01-01

    A novel technique for measurement of high frequency temperature fluctuations in unseeded gas flows using molecular Rayleigh scattering is investigated. The spectrum of laser light scattered from molecules in a gas flow is resolved using a Fabry-Perot interferometer. The width of the spectral peak is broadened by thermal motion of the molecules and hence is related to gas temperature. The interference fringe pattern containing spectral information is divided into four concentric regions using a series of mirrors angled with respect to one another. Light from each of these regions is directed towards photomultiplier tubes and sampled at 10 kHz using photon counting electronics. Monitoring the relative change in intensity within each region allows measurement of gas temperature. Independently monitoring the total scattered intensity provides a measure of gas density. This technique also has the potential to simultaneously measure a single component of flow velocity by monitoring the spectral peak location. Measurements of gas temperature and density are demonstrated using a low speed heated air jet surrounded by an unheated air co-flow. Mean values of temperature and density are shown for radial scans across the jet flow at a fixed axial distance from the jet exit plane. Power spectra of temperature and density fluctuations at several locations in the jet are also shown. The instantaneous measurements have fairly high uncertainty; however, long data records provide highly accurate statistically quantities, which include power spectra. Mean temperatures are compared with thermocouple measurements as well as the temperatures derived from independent density measurements. The accuracy for mean temperature measurements was +/- 7 K.

  7. Ultraviolet Rayleigh scatter imaging in atmospheric microdischarges for spatial temperature profiles

    NASA Astrophysics Data System (ADS)

    Caplinger, James; Adams, Steven; Hensley, Amber; Tolson, Boyd

    2014-10-01

    Spatially resolved temperature measurements within a microdischarge in atmospheric pressure air have been conducted using Rayleigh scattering of a pulsed ultraviolet laser. The scatter image intensity along the laser beam axis is proportional to the background gas target density and thus, according to the ideal gas law, is inversely proportional to gas translational temperature. By measuring the scatter image with and without a discharge, the temperature was determined in 1-dimension along the laser beam passing radially through the discharge. The 1-dimensional scattering intensity profiles were then used to generate 2-dimensional cross-sectional slices of temperature by transitioning the height of the laser beam. The cross-sectional temperature profiles exhibited a high degree of cylindrical symmetry with the radial width of the high temperature region expanding with increasing discharge current. Peak temperatures determined by Rayleigh scattering for each current were compared to temperatures derived from standard optical emission spectral analyses of N2(C-B) bands, where the calculated rotational temperatures from emission were in reasonable agreement with the Rayleigh translational temperature profiles. Air Force Office of Scientific Research.

  8. Translational Temperature Profiles in Atmospheric Air Microdischarges by Ultraviolet Rayleigh Scattering

    NASA Astrophysics Data System (ADS)

    Adams, Steven; Caplinger, James; Hensley, Amber; Tolson, Allen

    2014-03-01

    Spatially resolved temperature measurements within a microdischarge in atmospheric pressure air have been conducted using Rayleigh scattering of a pulsed ultraviolet laser. The scatter image intensity along the laser beam axis is proportional to the background gas target density and thus, according to the ideal gas law, is inversely proportional to gas translational temperature. By measuring the scatter image with and without a discharge, the temperature was determined in 1-dimension along the laser beam passing radially through the discharge. The 1-dimensional scattering intensity profiles were then used to generate 2-dimensional cross-sectional slices of temperature by transitioning the height of the laser beam. The cross-sectional temperature profiles exhibited a high degree of cylindrical symmetry with the radial width of the high temperature region expanding with increasing discharge current. Peak temperatures determined by Rayleigh scattering for each current were compared to temperatures derived from standard optical emission spectral analyses of N2(C-B) bands, where the calculated rotational temperatures from emission were in reasonable agreement with the Rayleigh translational temperature profiles.

  9. Scattered light in photolithographic lenses

    NASA Astrophysics Data System (ADS)

    Kirk, Joseph P.

    1994-05-01

    Scattered light, flare, is present in the images formed by all photolithography lenses and it reduces lithographic process tolerances. It varies from lens to lens and with time, but is easily measured by observation of images of opaque objects formed in positive photoresist. The scattered light halo of a lens is modeled and the model used to estimate the flare for any reticle used with that lens.

  10. Light Scattering Study of Titania Aerosols

    NASA Astrophysics Data System (ADS)

    Oh, Choonghoon; Sorensen, Chris

    1997-03-01

    We studied the fractal morphology of titania aerosols by light scattering. Titania aerosols were generated by the thermal decomposition of titanium tetraisopropoxide (TTIP) in a silica tube furnace. TTIP was evaporated at temperatures up to 80^circC and its vapor was carried by dry nitrogen to a furnace with temperature in the range of 400 - 600^circC. A TEM analysis of the generated particles showed a typical DLCA structure with a monomer diameter about 50 nm. The particles were then made to flow through a narrow outlet as a laminar stream. The light scattering from these particles was measured using a He-Ne laser as a light source. The measured structure factor clearly showed the Rayleigh, Guinier, and fractal regimes. The fractal morphological parameters, such as the cluster radius of gyration, the fractal dimension, and the fractal prefactor were studied from the structure factor as a function of particle generation conditions. The cluster radius of gyration was about 1 μm and showed a modest dependency on the generation conditions. The fractal dimension was about 1.7 in all cases. These results are in good agreement with the TEM analysis.

  11. RAYLEIGH SCATTERING IN THE ATMOSPHERE OF THE WARM EXO-NEPTUNE GJ 3470B

    SciTech Connect

    Dragomir, Diana; Benneke, Björn; Pearson, Kyle A.; Crossfield, Ian J. M.; Barman, Travis; Eastman, Jason; Biddle, Lauren I.

    2015-12-01

    GJ 3470b is a warm Neptune-size planet transiting an M dwarf star. Like the handful of other small exoplanets for which transmission spectroscopy has been obtained, GJ 3470b exhibits a flat spectrum in the near- and mid-infrared. Recently, a tentative detection of Rayleigh scattering in its atmosphere has been reported. This signal manifests itself as an observed increase of the planetary radius as a function of decreasing wavelength in the visible. We set out to verify this detection and observed several transits of this planet with the LCOGT network and the Kuiper telescope in four different bands (Sloan g, Sloan i, Harris B, and Harris V). Our analysis reveals a strong Rayleigh scattering slope, thus confirming previous results. This makes GJ 3470b the smallest known exoplanet with a detection of Rayleigh scattering. We find that the most plausible scenario is a hydrogen/helium-dominated atmosphere covered by clouds which obscure absorption features in the infrared and hazes which give rise to scattering in the visible. Our results demonstrate the feasibility of exoplanet atmospheric characterization from the ground, even with meter-class telescopes.

  12. [Determination of Trace Boron Based on Gold Nanorod Plasmonic Resonance Rayleigh Scattering Energy Transfer to the Coordinate].

    PubMed

    Ye, Ling-ling; Li, Ting-sheng; Luo, Yang-he; Wen, Gui-qing; Liang, Ai-hui; Jiang, Zhi-liang

    2015-05-01

    B is a necessary trace element for human and animals, but the excess intake of B caused poison. Thus, it is very important to determination of B in foods and water. The target of this study is development of a new, sensitive and selective resonance Rayleigh scattering energy transfer (RRS-ET) for the determination of B. The combination of energy transfer with resonance Rayleigh scattering (RRS) has developed a new technology called RRS-ET, which can realize selective and sensitive detection of boric acid. The gold nanorods in diameter of 12 nm and length of 37 nm were prepared by the seed growth procedure. In pH 5. 6 NH4 Ac-HAc buffer solution and in the presence of azomethine-H (AMH), the gold nanorod particles exhibited a strong resonance Rayleigh scattering (RRS) peak at 404 nm. In the presence of boric acid, it reacts with AMH to form AMH-boric acid (AMH-B) complexes. When the complexe as a receptor close to the gold nanorod as a donor, the resonance Rayleigh scattering energy transfer (RRS-ET) take placed that resulted in the Rayleigh scattering signal quenching. With the increase of the concentration of boric acid, the formed complexes increased, the scattering light energy of gold nanorod transfer to the complexes increased, resulting in the Rayleigh scattering intensity linearly reduced at 404 nrn. The decreased RRS intensity responds linearly to the concentration of boron over 10~750 ng . mL-1 B, with a regress equation of ΔI404 nm =3. 53c+24 and a detection of 5 ng mL-1 B. The influence of coexistence substances on the RRS-ET determination of 2. 3 X 10(-7) mol . L-1 B was considered in details. Results showed that this new RRS-ET method is of high selectivity, that is, 4 X 10(-4) mol . L-1 Mn2+, Cd2+, Zn2+, Bi+, Na+, Al3+, glucose, Hg2+, IO3-, F-, SO(2-)3, SiO3-, NO3-, CIO4-, H2O2, mannitol, glycerol, and ethylene glycol, 4X 10(-5) mol . L-1 L-tyrosine, and 2 X 10(-4) mol . L-1 L-glutamic acid do not interfere with the determination. Based on this, a new

  13. Rayleigh Scattering Diagnostic Used to Measure Velocity and Density Fluctuation Spectra

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Panda, Jayanta; Elam, Kristie A.

    2003-01-01

    A new, molecular Rayleigh-scattering-based flow diagnostic developed at the NASA Glenn Research Center has been used for the first time to measure the power spectrum of both gas density and radial velocity components in the plumes of high-speed jets. The objective of the work is to develop an unseeded, nonintrusive dynamic measurement technique for studying turbulent flows in NASA test facilities. This technique provides aerothermodynamic data not previously obtainable. It is particularly important for supersonic flows, where hot wire and pitot probes are difficult to use and disturb the flow under study. The effort is part of the nonintrusive instrumentation development program supporting propulsion research at the NASA Glenn Research Center. In particular, this work is measuring fluctuations in flow velocity, density, and temperature for jet noise studies. These data are valuable to researchers studying the correlation of flow fluctuations with far-field noise. One of the main objectives in jet noise research is to identify noise sources in the jet and to determine their contribution to noise generation. The technique is based on analyzing light scattered from molecules within the jet using a Fabry-Perot interferometer operating in a static imaging mode. The PC-based data acquisition system can simultaneously sample velocity and density data at rates to about 100 kHz and can handle up to 10 million data records. We used this system to interrogate three different jet nozzle designs in a Glenn free-jet facility. Each nozzle had a 25.4-mm exit diameter. One was convergent, used for subsonic flow measurements and to produce a screeching underexpanded jet with a fully expanded Mach number of 1.42. The other nozzles (Mach 1.4 and 1.8) were convergent-divergent types. The radial component of velocity and gas density were simultaneously measured in this work.

  14. Reduction of double Rayleigh scattering noise in distributed Raman amplifiers employing higher-order pumping.

    PubMed

    Bolognini, Gabriele; Bononi, Alberto

    2009-04-27

    We present a theoretical study of the performance of distributed Raman amplifiers with higher order pumping schemes, focusing in particular on double Rayleigh scattering (DRS) noise. Results show an unexpected significant DRS noise reduction for pumping order higher than third, allowing for an overall performance improvement of carefully designed distributed amplifiers, ensuring a large optical signal-to-noise ratio improvement together with reduced DRS-induced penalties.

  15. Remote-sensing gas measurements with coherent Rayleigh-Brillouin scattering

    DOE PAGESBeta

    Gerakis, A.; Shneider, M. N.; Stratton, B. C.

    2016-07-21

    Here, we measure the coherent Rayleigh-Brillouin scattering (CRBS) signal integral as a function of the recorded gas pressure in He, Co2, SF6, and air, and confirm the already established quadratic dependence of the signal on the gas density. Finally, we propose the use of CRBS as an effective diagnostic for the remote measurement of gas' density (pressure) and temperature, as well as polarizability, for gases of known composition.

  16. Development of Filtered Rayleigh Scattering for Accurate Measurement of Gas Velocity

    NASA Technical Reports Server (NTRS)

    Miles, Richard B.; Lempert, Walter R.

    1995-01-01

    The overall goals of this research were to develop new diagnostic tools capable of capturing unsteady and/or time-evolving, high-speed flow phenomena. The program centers around the development of Filtered Rayleigh Scattering (FRS) for velocity, temperature, and density measurement, and the construction of narrow linewidth laser sources which will be capable of producing an order MHz repetition rate 'burst' of high power pulses.

  17. Light Scattering From Fractal Titania Aggregates

    NASA Astrophysics Data System (ADS)

    Pande, Rajiv; Sorensen, Christopher M.

    1996-03-01

    We studied the fractal morphology of titania aggregates by light scattering. Titanium dioxide particles were generated by the thermal decomposition of titanium tetra-isopropoxide(TTIP) in a glass furnace at various temperatures in the range of 100 - 500^o C. We scattered vertically polarized He-Ne laser (λ = 6328Ålight from a laminar aerosol stream of particles and measured the optical structure factor. This structure factor shows Rayleigh, Guinier, fractal and Porod regimes. The radius of gyration Rg was determined from the Guinier analysis. The data were then fit to the Fisher-Burford form to determine the fractal dimension of about 2.0. This fit also delineated the crossover from the fractal to Porod regime, which can be used to determine the monomer particle size of about 0.1 μm. These optical measurements will be compared to electron microscope analysis of aggregates collected from the aerosol. This work was supported by NSF grant CTS-9908153.

  18. Rayleigh scattering correlation spectroscopy on diffusion dynamics of nanoparticles under intense laser irradiation

    NASA Astrophysics Data System (ADS)

    Hee, Ping-Yu; Uwada, Takayuki; Okano, Kazunori; Miura, Atsushi; Masuhara, Hiroshi

    2013-09-01

    Rayleigh scattering correlation microspectroscopy is developed and applied to study diffusion dynamics of some nanospheres in water. It was clearly found that the diffusion constant of gold nanoparticles decreased with increasing excitation laser power at the excitation wavelength of higher absorption cross section. This behavior was explained in terms of a coupling between laser trapping by the scattering excitation laser itself and laser heating of the particle. In the case of non-absorbing nanospheres such as silica and polystyrene, the excitation power dependence can be ascribed only to the laser trapping. Experimental setup is introduced, theoretical formulation is described, and future development of this measurement is considered.

  19. Rayleigh approximation for the scattering of small partially charged sand particles.

    PubMed

    Li, Xingcai; Min, Xing; Liu, Dandan

    2014-07-01

    Based on the Rayleigh approximation, this paper presents the electromagnetic scattering properties of the small partially charged isotropic sphere and those of a similar anisotropic sphere and then discusses the effect of surface charges on particles' optical properties. The numerical simulation results show that the surface charges on a charged particle can enhance the scattering of the incident waves, and the effect on an anisotropic charged sphere is much greater than that on an isotropic charged particle. Therefore it is necessary to consider the medium property (isotropic or anisotropic) and electric effects of dust particles in the remote sensing of sandstorms. PMID:25121437

  20. Standoff detection of large organic molecules using Rydberg fingerprint spectroscopy and microwave Rayleigh scattering

    SciTech Connect

    Rudakov, Fedor M; Zhang, Zhili

    2012-01-01

    We present a technique for nonintrusive and standoff detection of large organic molecules using coherent microwave Rayleigh scattering from plasma produced by structure sensitive photoionization through Rydberg states. We test the method on 1,4-diazobicyclooctane. Transitions between the 3s Rydberg state and higher lying Rydberg states are probed using two-color photoionization with 266?nm photons and photons in the range of 460-2400 nm. Photoionization is detected using microwave radiation, which is scattered by the unbounded electrons. Highly resolved Rydberg spectra are acquired in vacuum and in air.

  1. Polarized light scattering from individual semiconductor nanowires

    NASA Astrophysics Data System (ADS)

    Wu, Jian

    This thesis addresses the light scattering, particularly Raman and Rayleigh scattering from quasi one dimensional semiconductor nanowires, such as Zn1-xMnxS and GaP nanowires. Many of the results stem from measurements of individual wires. Four original works are presented in the thesis: (1) The growth of diluted magnetic semiconductor (DMS) Zn1-xMnxS (0≤x<0.6) nanowires using a three-zone furnace and two solid sources is reported (Chapter 2.4). The vibrational properties of the DMS nanowires with different Zn/Mn ratios were studied by correlating their Raman scattering spectra with the composition and structure measured by x-Ray energy dispersive spectroscopy (XEDS) and selected area electron diffraction (SAD). We find that the transverse optical (TO) phonon band disappears at the lowest Mn concentrations, while the longitudinal optical (LO) phonon band position was found insensitive to x. Three additional Raman bands were observed between the ZnS q=0 TO and LO phonons when Mn atoms were present in the nanowires (Chapter 5); (2) Polarized Raman scattering on individual crystalline GaP nanowires with diameters 40 individual crystalline GaP nanowires with diameters 40scattering intensity function I(theta) ˜ cos4theta where theta is the angle between nanowire axis and the incident laser polarization. For larger diameter (70scattering are proposed to explain the experimental data. This work realizes a fundamental understanding of Raman scattering in semiconductor nanowires and furthermore, the antenna effects are essential to the analysis of all electro-optic effects in small diameter filaments (Chapter 7); (3) Results of polarized Rayleigh back-scattering studies are

  2. Multiple light scattering methods for multiphase flow diagnostics

    NASA Astrophysics Data System (ADS)

    Estevadeordal, Jordi

    2015-11-01

    Multiphase flows of gases and liquids containing droplets, bubbles, or particulates present light scattering imaging challenges due to the interference from each phase, such as secondary reflections, extinctions, absorptions, and refractions. These factors often prevent the unambiguous detection of each phase and also produce undesired beam steering. The effects can be especially complex in presence of dense phases, multispecies flows, and high pressure environments. This investigation reports new methods for overcoming these effects for quantitative measurements of velocity, density, and temperature fields. The methods are based on light scattering techniques combining Mie and filtered Rayleigh scattering and light extinction analyses and measurements. The optical layout is designed to perform multiple property measurements with improved signal from each phase via laser spectral and polarization characterization, etalon decontamination, and use of multiple wavelengths and imaging detectors.

  3. Long-range measurement of Rayleigh scatter signature beyond laser coherence length based on coherent optical frequency domain reflectometry.

    PubMed

    Ohno, Shingo; Iida, Daisuke; Toge, Kunihiro; Manabe, Tetsuya

    2016-08-22

    Long-range C-OFDR measurement of fiber Rayleigh scatter signature is described. The Rayleigh scatter signature, which is an interference pattern of backscatters from the random refractive indices in fibers, is known to be applicable to fiber identification and temperature or strain sensing by measuring its repeatability and its spectral shift. However, these applications have not been realized at ranges beyond the laser coherence length since laser phase noise degrades its repeatability. This paper proposes and demonstrates a method for analyzing the optical power spectrum of local Rayleigh backscatter to overcome the limitation imposed by laser phase noise. The measurable range and spatial performance are also investigated experimentally with respect to the remaining phase noise and noise reduction by signal averaging with the proposed method. The feasibility of Rayleigh scatter signature measurement for long-range applications is confirmed. PMID:27557243

  4. Planar laser light scattering technique for measurement of nonspherical particles

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Woo; Choi, Man Soo; Jeong, Dae Hwa; Lee, Hyo Hyung

    2004-09-01

    Small particles are one of the biggest sources that cause loss in semiconductor and flat panel display industry. Therefore, it is important to control them during their manufacturing process. To achieve this goal, exact measurement of particles is first required. Laser light scattering is the most widely used technique for diagnosis of particles because it does not disturb flow field and enables real time and spatially resolved analysis. Measurement of nonspherical aggregates comprised of small primary particles is difficult compared with spherical particles because they have very complex morphology. In addition, most researches on aggregates using light scattering are limited to point measurement, which requires much time to inspect large area and is difficult to observe unsteady phenomenon. Motivated by this, we have developed a laser light scattering method for simultaneous measurement of spatial distributions of aggregate size and morphology. Silica aggregates that were generated in Methane/air premixed flame were used as test particles. Multiangular planar light scattering measurement was carried out using a sheet beam of Ar ion laser and an intensified charge coupled device (ICCD) camera as a light source and a detector, respectively. The result was interpreted based on the Rayleigh-Debye-Gans scattering theory for fractal aggregates to obtain the mean radius of gyration and fractal dimension that are the parameters characterizing aggregate size and morphology. The suitability of our new technique was confirmed by experiment using conventional light scattering.

  5. Geometry and quadratic nonlinearity of charge transfer complexes in solution using depolarized hyper-Rayleigh scattering.

    PubMed

    Pandey, Ravindra; Ghosh, Sampa; Mukhopadhyay, S; Ramasesha, S; Das, Puspendu K

    2011-01-28

    We report large quadratic nonlinearity in a series of 1:1 molecular complexes between methyl substituted benzene donors and quinone acceptors in solution. The first hyperpolarizability, β(HRS), which is very small for the individual components, becomes large by intermolecular charge transfer (CT) interaction between the donor and the acceptor in the complex. In addition, we have investigated the geometry of these CT complexes in solution using polarization resolved hyper-Rayleigh scattering (HRS). Using linearly (electric field vector along X direction) and circularly polarized incident light, respectively, we have measured two macroscopic depolarization ratios D=I(2ω,X,X)/I(2ω,Z,X) and D(')=I(2ω,X,C)/I(2ω,Z,C) in the laboratory fixed XYZ frame by detecting the second harmonic scattered light in a polarization resolved fashion. The experimentally obtained first hyperpolarizability, β(HRS), and the value of macroscopic depolarization ratios, D and D('), are then matched with the theoretically deduced values from single and double configuration interaction calculations performed using the Zerner's intermediate neglect of differential overlap self-consistent reaction field technique. In solution, since several geometries are possible, we have carried out calculations by rotating the acceptor moiety around three different axes keeping the donor molecule fixed at an optimized geometry. These rotations give us the theoretical β(HRS), D and D(') values as a function of the geometry of the complex. The calculated β(HRS), D, and D(') values that closely match with the experimental values, give the dominant equilibrium geometry in solution. All the CT complexes between methyl benzenes and chloranil or 1,2-dichloro-4,5-dicyano-p-benzoquinone investigated here are found to have a slipped parallel stacking of the donors and the acceptors. Furthermore, the geometries are staggered and in some pairs, a twist angle as high as 30° is observed. Thus, we have demonstrated in

  6. A Theoretical Light Scattering Model of Nanoparticle Laser Tweezers

    NASA Technical Reports Server (NTRS)

    Lock, James A.

    2003-01-01

    Accomplishments this reporting period include: 1. derived, programmed, checked, and tested the Mie light scattering theory formulas for the radiation trapping force for both the on-axis and off-axis geometry of the trapping beam plus trapped spherical particle; 2. verified that the computed radiation trapping force for a freely propagating focused Gaussian laser beam incident on a spherical particle agrees with previous published calculations; 3. compared the small particle size and large particle size limits of the Mie calculation with the results of Rayleigh scattering theory and ray scattering theory, respectively and verified that the comparison is correct for Rayleigh scattering theory but found that ray theory omits an important light scattering effect included in the Mie theory treatment; 4. generalized the calculation of the radiation trapping force on a spherical particle in the on-axis geometry from a freely propagating focused Gaussian laser beam to the realistic situation of a Gaussian beam truncated and focused by a high numerical aperture oil-immersion microscope objective lens and aberrated by the interface between the microscope cover slip and the liquid-filled sample volume; and 5. compared the calculated radiation trapping force for this geometry with the results of previously published experiments and found that the agreement is better than when using previously developed theories.

  7. Novel technique for distributed fibre sensing based on coherent Rayleigh scattering measurements of birefringence

    NASA Astrophysics Data System (ADS)

    Lu, Xin; Soto, Marcelo A.; Thévenaz, Luc

    2016-05-01

    A novel distributed fibre sensing technique is described and experimentally validated, based on birefringence measurements using coherent Rayleigh scattering. It natively provides distributed measurements of temperature and strain with more than an order of magnitude higher sensitivity than Brillouin sensing, and requiring access to a single fibre-end. Unlike the traditional Rayleigh-based coherent optical time-domain reflectometry, this new method provides absolute measurements of the measurand and may lead to a robust discrimination between temperature and strain in combination with another technique. Since birefringence is purposely induced in the fibre by design, large degrees of freedom are offered to optimize and scale the sensitivity to a given quantity. The technique has been validated in 2 radically different types of birefringent fibres - elliptical-core and Panda polarization-maintaining fibres - with a good repeatability.

  8. Temperature Deviations in the Midlatitude Mesosphere During Stratospheric Warmings as Measured with Rayleigh-Scatter Lidar

    NASA Astrophysics Data System (ADS)

    Sox, Leda; Wickwar, Vincent; Fish, Chad; Herron, Joshua P.

    2016-06-01

    While mesospheric temperature anomalies associated with Sudden Stratospheric Warmings (SSWs) have been observed extensively in the polar regions, observations of these anomalies at midlatitudes are sparse. The original Rayleigh-scatter lidar that operated at the Atmospheric Lidar Observatory (ALO; 41.7°N, 111.8°W) in the Center for Atmospheric and Space Sciences (CASS) on the campus of Utah State University (USU) collected an extensive set of temperature data for 11 years in the 45-90 km altitude range. This work focuses on the extensive Rayleigh lidar observations made during six major SSW events that occurred between 1993 and 2004, providing a climatological study of the midlatitude mesospheric temperatures during these SSW events. An overall disturbance pattern was observed in the mesospheric temperatures during these SSWs. It included coolings in the upper mesosphere, comparable to those seen in the polar regions during SSW events, and warmings in the lower mesosphere.

  9. Estimation of effective atomic number in the Rayleigh to Compton scattering ratio using different methods

    NASA Astrophysics Data System (ADS)

    Kurudirek, M.; Büyükyıldız, M.

    2016-06-01

    The Rayleigh to Compton scattering ratio (R/C) is a very convenient parameter, which can be utilized in material analysis and estimating effective atomic number (Zeff). In the case for a relatively low scattering angle, for which the energy of the Compton scattered photons is not very much different from that of incident photons, the corrections due to self-absorption for Rayleigh and Compton scattering will be roughly equal. Therefore, it enables a result to be obtained which is almost independent of X-ray attenuation inside the sample and it will depend only on the material under investigation. The most frequently used method for calculation of Zeff available in literature is plotting R/C of elements as a function of atomic number and constituting the best fit curve. From this fit curve, the respective Zeff can be determined using R/C of the material. In the present study, we report Zeff of different materials using different methods such as interpolation and direct methods as possible alternatives to the most common fitting method. The results were compared with the experiments wherever possible. The agreement between interpolation method and the fitting method was found to be very satisfactory as relative changes (%) were always less than 9% while the direct method results with somehow significantly higher values of Zeff when compared to the other methods.

  10. Temperature-dependent bulk viscosity of nitrogen gas determined from spontaneous Rayleigh-Brillouin scattering.

    PubMed

    Gu, Ziyu; Ubachs, Wim

    2013-04-01

    Values for the bulk viscosity η(b) of molecular nitrogen gas (N2) were derived from spontaneous Rayleigh-Brillouin scattering at ultraviolet wavelengths (λ=366.8 nm) and at a 90° scattering angle. Analysis of the scattering profiles yields values showing a linear increasing trend, ranging from η(b)=0.7×10(-5) to 2.0×10(-5) kg·m(-1)·s(-1) in the temperature interval from 255 to 340 K. The present values, pertaining to hypersound acoustics at frequencies in the gigahertz domain, are found to be in agreement with results from acoustic attenuation experiments in N2 performed at megahertz frequencies.

  11. Rayleigh scatter in kilovoltage x-ray imaging: is the independent atom approximation good enough?

    PubMed

    Poludniowski, G; Evans, P M; Webb, S

    2009-11-21

    Monte Carlo simulation is the gold standard method for modelling scattering processes in medical x-ray imaging. General-purpose Monte Carlo codes, however, typically use the independent atom approximation (IAA). This is known to be inaccurate for Rayleigh scattering, for many materials, in the forward direction. This work addresses whether the IAA is sufficient for the typical modelling tasks in medical kilovoltage x-ray imaging. As a means of comparison, we incorporate a more realistic 'interference function' model into a custom-written Monte Carlo code. First, we conduct simulations of scatter from isolated voxels of soft tissue, adipose, cortical bone and spongiosa. Then, we simulate scatter profiles from a cylinder of water and from phantoms of a patient's head, thorax and pelvis, constructed from diagnostic-quality CT data sets. Lastly, we reconstruct CT numbers from simulated sets of projection images and investigate the quantitative effects of the approximation. We show that the IAA can produce errors of several per cent of the total scatter, across a projection image, for typical x-ray beams and patients. The errors in reconstructed CT number, however, for the phantoms simulated, were small (typically < 10 HU). The IAA can therefore be considered sufficient for the modelling of scatter correction in CT imaging. Where accurate quantitative estimates of scatter in individual projection images are required, however, the appropriate interference functions should be included.

  12. Rayleigh scatter in kilovoltage x-ray imaging: is the independent atom approximation good enough?

    NASA Astrophysics Data System (ADS)

    Poludniowski, G.; Evans, P. M.; Webb, S.

    2009-11-01

    Monte Carlo simulation is the gold standard method for modelling scattering processes in medical x-ray imaging. General-purpose Monte Carlo codes, however, typically use the independent atom approximation (IAA). This is known to be inaccurate for Rayleigh scattering, for many materials, in the forward direction. This work addresses whether the IAA is sufficient for the typical modelling tasks in medical kilovoltage x-ray imaging. As a means of comparison, we incorporate a more realistic 'interference function' model into a custom-written Monte Carlo code. First, we conduct simulations of scatter from isolated voxels of soft tissue, adipose, cortical bone and spongiosa. Then, we simulate scatter profiles from a cylinder of water and from phantoms of a patient's head, thorax and pelvis, constructed from diagnostic-quality CT data sets. Lastly, we reconstruct CT numbers from simulated sets of projection images and investigate the quantitative effects of the approximation. We show that the IAA can produce errors of several per cent of the total scatter, across a projection image, for typical x-ray beams and patients. The errors in reconstructed CT number, however, for the phantoms simulated, were small (typically < 10 HU). The IAA can therefore be considered sufficient for the modelling of scatter correction in CT imaging. Where accurate quantitative estimates of scatter in individual projection images are required, however, the appropriate interference functions should be included.

  13. A systematic study of Rayleigh-Brillouin scattering in air, N2, and O2 gases

    NASA Astrophysics Data System (ADS)

    Gu, Ziyu; Ubachs, Wim

    2014-09-01

    Spontaneous Rayleigh-Brillouin scattering experiments in air, N2, and O2 have been performed for a wide range of temperatures and pressures at a wavelength of 403 nm and at a 90° scattering angle. Measurements of the Rayleigh-Brillouin spectral scattering profile were conducted at high signal-to-noise ratio for all three species, yielding high-quality spectra unambiguously showing the small differences between scattering in air, and its constituents N2 and O2. Comparison of the experimental spectra with calculations using the Tenti S6 model, developed in the 1970s based on linearized kinetic equations for molecular gases, demonstrates that this model is valid to high accuracy for N2 and O2, as well as for air. After previous measurements performed at 366 nm, the Tenti S6 model is here verified for a second wavelength of 403 nm, and for the pressure-temperature parameter space covered in the present study (250-340 K and 0.6-3 bars). In the application of the Tenti S6 model, based on the transport coefficients of the gases, such as thermal conductivity κ, internal specific heat capacity cint and shear viscosity η, as well as their temperature dependencies taken as inputs, values for the more elusive bulk viscosity ηb for the gases are derived by optimizing the model to the measurements. It is verified that the bulk viscosity parameters obtained from previous experiments at 366 nm are valid for wavelengths of 403 nm. Also for air, which is treated as a single-component gas with effective gas transport coefficients, the Tenti S6 treatment is validated for 403 nm as for the previously used wavelength of 366 nm, yielding an accurate model description of the scattering profiles for a range of temperatures and pressures, including those of relevance for atmospheric studies. It is concluded that the Tenti S6 model, further verified in the present study, is applicable to LIDAR applications for exploring the wind velocity and the temperature profile distributions of the

  14. Correction of radiation absorption on biological samples using Rayleigh to Compton scattering ratio

    NASA Astrophysics Data System (ADS)

    Pereira, Marcelo O.; Conti, Claudio de Carvalho; dos Anjos, Marcelino J.; Lopes, Ricardo T.

    2012-06-01

    The aim of this work was to develop a method to correct the absorbed radiation (the mass attenuation coefficient curve) in low energy (E < 30 keV) applied to a biological matrix based on the Rayleigh to Compton scattering ratio and the effective atomic number. For calibration, scattering measurements were performed on standard samples of radiation produced by a gamma-ray source of 241Am (59.54 keV) also applied to certified biological samples of milk powder, hay powder and bovine liver (NIST 1557B). In addition, six methods of effective atomic number determination were used as described in literature to determinate the Rayleigh to Compton scattering ratio (R/C), in order to calculate the mass attenuation coefficient. The results obtained by the proposed method were compared with those obtained using the transmission method. The experimental results were in good agreement with transmission values suggesting that the method to correct radiation absorption presented in this paper is adequate for biological samples.

  15. Half a century of light scatter metrology and counting

    NASA Astrophysics Data System (ADS)

    Stover, John C.

    2014-09-01

    Back in the early days Bill Wolf once said something like: "The guy with the lowest scatter measurement is closest to the right answer." He was often right then - but not anymore. Everything has changed. Today measurements are limited by Rayleigh scatter from the air - not the instrument. We have both written and physical standards and everybody spells BRDF the same way. In the time it takes to give this talk, over 100,000 silicon wafers will be inspected around the world using a few thousand scatterometers - average price about one million dollars each. The way the world illuminates everything from homes to football fields is changing with the advent of high brightness LED's and these lighting systems are designed using a combination of scatter metrology and analysis techniques - many of which were started at The Optical Sciences Center. This paper reviews two major highlights in half a century of scatter metrology progress.

  16. Coherent effects in the scattering of light from two-dimensional rough metal surfaces.

    PubMed

    Letnes, Paul Anton; Nordam, Tor; Simonsen, Ingve

    2013-06-01

    We investigate numerically multiple light-scattering phenomena for two-dimensional randomly rough metallic surfaces, where surface plasmon polaritons (SPPs) mediate several surface scattering effects. The scattering problem is solved by numerical solution of the reduced Rayleigh equation for reflection. The multiple scattering phenomena of enhanced backscattering and enhanced forward scattering are observed in the same system, and their presence is due to the excitation of SPPs. The numerical results discussed are qualitatively different from previous results for one-dimensionally rough surfaces, as one-dimensional surfaces have a limited influence on the polarization of light.

  17. Spectral structure of laser light scattering revisited: bandwidths of nonresonant scattering lidars.

    PubMed

    She, C Y

    2001-09-20

    It is well known that scattering lidars, i.e., Mie, aerosol-wind, Rayleigh, high-spectral-resolution, molecular-wind, rotational Raman, and vibrational Raman lidars, are workhorses for probing atmospheric properties, including the backscatter ratio, aerosol extinction coefficient, temperature, pressure, density, and winds. The spectral structure of molecular scattering (strength and bandwidth) and its constituent spectra associated with Rayleigh and vibrational Raman scattering are reviewed. Revisiting the correct name by distinguishing Cabannes scattering from Rayleigh scattering, and sharpening the definition of each scattering component in the Rayleigh scattering spectrum, the review allows a systematic, logical, and useful comparison in strength and bandwidth between each scattering component and in receiver bandwidths (for both nighttime and daytime operation) between the various scattering lidars for atmospheric sensing. PMID:18360530

  18. Generation of a super-Rayleigh speckle field via a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Li, Xinzhong; Tai, Yuping; Li, Hehe; Wang, Jingge; Wang, Hui; Nie, Zhaogang

    2016-04-01

    This study investigated the generation method and properties of a super-Rayleigh speckle field that had a contrast value greater than 1. First, an exponential factor was added to the complex amplitude of the Rayleigh speckle, and then, its inverse Fourier-transformed phase matrix was applied to a spatial light modulator (SLM). As the collimated light beam illuminated the SLM, the super-Rayleigh speckle field was formed at the SLM's Fourier plane. The effects of the exponential factor, size of the macro-pixel of the SLM, and diameter of the entrance pupil on the contrast values of the super-Rayleigh speckle patterns were investigated. Especially, the influence of different macro-pixel sizes of the SLM was systematically studied. Moreover, the stability region of the super-Rayleigh speckle field was examined. The experimental results showed that the contrast values of the super-Rayleigh speckle field increased exponentially as the exponential factor increased under the same conditions. In addition, the contrast values increased as the size of the macro-pixel or diameter of the entrance pupil increased. Furthermore, as the pupil diameter increased, the width of the stability region decreased according to a negative quadratic index that corresponded to the longitudinal length of a single speckle.

  19. A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements

    NASA Technical Reports Server (NTRS)

    Otugen, M. Volkan

    1997-01-01

    Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of

  20. Founding fathers of light scattering and surface-enhanced Raman scattering.

    PubMed

    Kerker, M

    1991-11-20

    One can view our comprehension of surface-enhanced Raman scattering, particularly that by colloidal dispersions of metal sols, as the merging of two traditions in light-scattering theory and practice. One of these originated with Michael Faraday's work on brilliantly colored metal sols, which was taken up by Richard Zsigmondy and then by Gustav Mie, who accounted for the colors by electromagnetic-scattering theory. The other tradition starts with John Tyndall's work with aerosols, which stimulated Lord Rayleigh's entry into the field. Lord Rayleigh was perplexed by observations made with sulfur hydrosols, which in turn were explored by C. V. Raman. Raman's extensive work in light scattering led to his subsequent discovery of the Raman effect. These two traditions were then intertwined when it was shown that the same physical effect that caused Faraday's sols to exhibit their brilliant colors was also the origin of the enhancement of Raman signals from molecules adsorbed on the metal particles that compose these sols.

  1. Light Scattering in Exoplanet Transits

    NASA Astrophysics Data System (ADS)

    Robinson, Tyler D.; Fortney, Jonathan J.

    2016-10-01

    Transit spectroscopy is currently the leading technique for studying exoplanet atmospheric composition, and has led to the detection of molecular species, clouds, and/or hazes for numerous worlds outside the Solar System. The field of exoplanet transit spectroscopy will be revolutionized with the anticipated launch of NASA's James Webb Space Telescope (JWST) in 2018. Over the course of the design five year mission for JWST, the observatory is expected to provide in-depth observations of many tens of transiting exoplanets, including some worlds in the poorly understood 2–4 Earth-mass regime. As the quality of transit spectrum observations continues to improve, so should models of exoplanet transits. Thus, certain processes initially thought to be of second-order importance should be revisited and possibly added to modeling tools. For example, atmospheric refraction, which was commonly omitted from early transit spectrum models, has recently been shown to be of critical importance in some terrestrial exoplanet transits. Beyond refraction, another process that has seen little study with regards to exoplanet transits is light multiple scattering. In most cases, scattering opacity in exoplanet transits has been treated as equivalent to absorption opacity. However, this equivalence cannot always hold, such as in the case of a strongly forward scattering, weakly absorbing aerosol. In this presentation, we outline a theory of exoplanet transit spectroscopy that spans the geometric limit (used in most modern models) to a fully multiple scattering approach. We discuss a new technique for improving model efficiency that effectively separates photon paths, which tend to vary slowly in wavelength, from photon absorption, which can vary rapidly in wavelength. Using this newly developed approach, we explore situations where cloud or haze scattering may be important to JWST observations of gas giants, and comment on the conditions necessary for scattering to become a major

  2. Long-range orientation correlation in dipolar liquids probed by hyper-Rayleigh scattering.

    PubMed

    Shelton, David P

    2015-10-01

    Hyper-Rayleigh scattering (HRS) is sensitive to long-range molecular orientation correlation in isotropic liquids composed of dipolar molecules. The correlation functions that appear in the calculation of HRS mediated by the vector part of the first hyperpolarizability β are the same as the correlation functions for the homogeneous isotropic random vector fields that appear in the description of fluid turbulence. Recent experiments measuring the angle and polarization dependence of HRS from water find a dominant transverse mode contribution with amplitude independent of the scattering wavevector, and this observation of transverse mode HRS strongly constrains the form of the orientation correlation function. Analysis of these HRS results for water determines that the long-range molecular orientation correlation function varies as r(-3±ε) with |ε| < 0.03 on spatial scales up to 2000 nm. PMID:26450319

  3. Light Scattering by Nonspherical Particles

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael I.; Travis, Larry D.; Hovenier, Joop W.

    1998-01-01

    Improved understanding of electromagnetic scattering by nonspherical particles is important to many science and engineering disciplines and was the subject of the Conference on Light Scattering by Nonspherical Particles: Theory, Measurements, and Applications. The conference was held 29 September-1 October 1998 at the Goddard Institute for Space Studies in New York City and brought together 115 participants from 18 countries. The main objective of the conference was to highlight and summarize the rapid advancements in the field, including numerical methods for computing the single and multiple scattering of electromagnetic radiation by nonspherical and heterogeneous particles, measurement approaches, knowledge of characteristic features in scattering patterns, retrieval and remote sensing techniques, nonspherical particle sizing, and various practical applications. The conference consisted of twelve oral and one poster sessions. The presentations were loosely grouped based on broad topical categories. In each of these categories invited review talks highlighted and summarized specific active areas of research. To ensure a high-quality conference, all abstracts submitted had been reviewed by members of the Scientific Organizing Committee for technical merit and content. The conference program was published in the June 1998 issue of the Bulletin of the American Meteorological Society and is available on the World Wide Web at http://www.giss.nasa.gov/-crmim/conference/program.html. Authors of accepted papers and review presentations contributed to a volume of preprints published by the American Meteorological Society' and distributed to participants at the conference.

  4. Investigating the dynamics of laser induced sparks in atmospheric helium using Rayleigh and Thomson scattering

    SciTech Connect

    Nedanovska, E.; Nersisyan, G.; Lewis, C. L. S.; Riley, D.; Graham, W. G.; Morgan, T. J.; Hüwel, L.; Murakami, T.

    2015-01-07

    We have used optical Rayleigh and Thomson scattering to investigate the expansion dynamics of laser induced plasma in atmospheric helium and to map its electron parameters both in time and space. The plasma is created using 9 ns duration, 140 mJ pulses from a Nd:YAG laser operating at 1064 nm, focused with a 10 cm focal length lens, and probed with 7 ns, 80 mJ, and 532 nm Nd:YAG laser pulses. Between 0.4 μs and 22.5 μs after breakdown, the electron density decreases from 3.3 × 10{sup 17 }cm{sup −3} to 9 × 10{sup 13 }cm{sup −3}, while the temperature drops from 3.2 eV to 0.1 eV. Spatially resolved Thomson scattering data recorded up to 17.5 μs reveal that during this time the laser induced plasma expands at a rate given by R ∼ t{sup 0.4} consistent with a non-radiative spherical blast wave. This data also indicate the development of a toroidal structure in the lateral profile of both electron temperature and density. Rayleigh scattering data show that the gas density decreases in the center of the expanding plasma with a central scattering peak reemerging after about 12 μs. We have utilized a zero dimensional kinetic global model to identify the dominant particle species versus delay time and this indicates that metastable helium and the He{sub 2}{sup +} molecular ion play an important role.

  5. Investigating the dynamics of laser induced sparks in atmospheric helium using Rayleigh and Thomson scattering

    NASA Astrophysics Data System (ADS)

    Nedanovska, E.; Nersisyan, G.; Morgan, T. J.; Hüwel, L.; Murakami, T.; Lewis, C. L. S.; Riley, D.; Graham, W. G.

    2015-01-01

    We have used optical Rayleigh and Thomson scattering to investigate the expansion dynamics of laser induced plasma in atmospheric helium and to map its electron parameters both in time and space. The plasma is created using 9 ns duration, 140 mJ pulses from a Nd:YAG laser operating at 1064 nm, focused with a 10 cm focal length lens, and probed with 7 ns, 80 mJ, and 532 nm Nd:YAG laser pulses. Between 0.4 μs and 22.5 μs after breakdown, the electron density decreases from 3.3 × 1017 cm-3 to 9 × 1013 cm-3, while the temperature drops from 3.2 eV to 0.1 eV. Spatially resolved Thomson scattering data recorded up to 17.5 μs reveal that during this time the laser induced plasma expands at a rate given by R ˜ t0.4 consistent with a non-radiative spherical blast wave. This data also indicate the development of a toroidal structure in the lateral profile of both electron temperature and density. Rayleigh scattering data show that the gas density decreases in the center of the expanding plasma with a central scattering peak reemerging after about 12 μs. We have utilized a zero dimensional kinetic global model to identify the dominant particle species versus delay time and this indicates that metastable helium and the He2+ molecular ion play an important role.

  6. Resonance Rayleigh scattering technology as a new method for the determination of the inclusion constant of β-cyclodextrin

    NASA Astrophysics Data System (ADS)

    Li, Nianbing; Luo, Hongqun; Liu, Shaopu; Chen, Guonan

    2002-02-01

    The interaction of procaine hydrochloride and β-cyclodextrin in aqueous solution was studied using resonance Rayleigh scattering technology. The molar ratio of the inclusion complex was 1:1 established by spectrophotometry. The resonance Rayleigh scattering technology was first applied in the determination of the β-cyclodextrin inclusion constant. The inclusion constant of procaine hydrochloride-β-cyclodextrin complex Kf is 1.23×10 2 and 1.27×10 2 l mol -1 for method I and 1.15×10 2 and 1.21×10 2 l mol -1 for method II. These determination results were in correspondence with the results of the spectrophotometric and fluorescence methods. Therefore, the resonance Rayleigh scattering method can be used as a new technology for the determination of the inclusion constant.

  7. Demonstration of Imaging Flow Diagnostics Using Rayleigh Scattering in Langley 0.3-Meter Transonic Cryogenic Tunnel

    NASA Technical Reports Server (NTRS)

    Shirinzadeh, B.; Herring, G. C.; Barros, Toya

    1999-01-01

    The feasibility of using the Rayleigh scattering technique for molecular density imaging of the free-stream flow field in the Langley 0.3-Meter Transonic Cryogenic Tunnel has been experimentally demonstrated. The Rayleigh scattering was viewed with a near-backward geometry with a frequency-doubled output from a diode-pumped CW Nd:YAG laser and an intensified charge-coupled device camera. Measurements performed in the range of free-stream densities from 3 x 10(exp 25) to 24 x 10(exp 25) molecules/cu m indicate that the observed relative Rayleigh signal levels are approximately linear with flow field density. The absolute signal levels agree (within approx. 30 percent) with the expected signal levels computed based on the well-known quantities of flow field density, Rayleigh scattering cross section for N2, solid angle of collection, transmission of the optics, and the independently calibrated camera sensitivity. These results show that the flow field in this facility is primarily molecular (i.e., not contaminated by clusters) and that Rayleigh scattering is a viable technique for quantitative nonintrusive diagnostics in this facility.

  8. Rayleigh theory of ultrasound scattering applied to liquid-filled contrast nanoparticles

    NASA Astrophysics Data System (ADS)

    Flegg, M. B.; Poole, C. M.; Whittaker, A. K.; Keen, I.; Langton, C. M.

    2010-06-01

    We present a novel modified theory based upon Rayleigh scattering of ultrasound from composite nanoparticles with a liquid core and solid shell. We derive closed form solutions to the scattering cross-section and have applied this model to an ultrasound contrast agent consisting of a liquid-filled core (perfluorooctyl bromide, PFOB) encapsulated by a polymer shell (poly-caprolactone, PCL). Sensitivity analysis was performed to predict the dependence of the scattering cross-section upon material and dimensional parameters. A rapid increase in the scattering cross-section was achieved by increasing the compressibility of the core, validating the incorporation of high compressibility PFOB; the compressibility of the shell had little impact on the overall scattering cross-section although a more compressible shell is desirable. Changes in the density of the shell and the core result in predicted local minima in the scattering cross-section, approximately corresponding to the PFOB-PCL contrast agent considered; hence, incorporation of a lower shell density could potentially significantly improve the scattering cross-section. A 50% reduction in shell thickness relative to external radius increased the predicted scattering cross-section by 50%. Although it has often been considered that the shell has a negative effect on the echogeneity due to its low compressibility, we have shown that it can potentially play an important role in the echogeneity of the contrast agent. The challenge for the future is to identify suitable shell and core materials that meet the predicted characteristics in order to achieve optimal echogenity.

  9. What is the contribution of scattering to the Love-to-Rayleigh ratio in ambient microseismic noise?

    NASA Astrophysics Data System (ADS)

    Ziane, D.; Hadziioannou, C.

    2015-12-01

    Several observations show the existence of both Rayleigh and Love waves in the secondary microseism. While the Rayleigh wave excitation is well described by Longuet-Higgins, the process responsible for Love wave generation still needs further investigation. Several different mechanisms could excite Love waves in this frequency band: broadly speaking, we can differentiate between source effects, like pressure variations on the oblique sea floor, or internal effects in the medium along the propagation path, such as scattering and conversions. Here we will focus on the internal effects. We perform single scattering tests in 2D and 3D to gain a better understanding of the scattering radiation pattern and the conversion between P, S, Rayleigh and Love waves. Furthermore, we use random media with continuous variations of the elastic parameters to create a scattering regime similar to the Earths interior, e.g. Gaussian or von Karmann correlation functions. The aim is to explore the contribution of scattering along the propagation path to the observed Love to Rayleigh wave energy ratios, assuming a purely vertical force source mechanism. We use finite different solvers to calculate the synthetic seismograms, and to separate the different wave types we measure the rotational and divergent components of the wave field.

  10. Development of a Rayleigh Scattering Diagnostic for Time-Resolved Gas Flow Velocity, Temperature, and Density Measurements in Aerodynamic Test Facilities

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.; Sung, Chih-Jen

    2007-01-01

    A molecular Rayleigh scattering technique is developed to measure time-resolved gas velocity, temperature, and density in unseeded turbulent flows at sampling rates up to 32 kHz. A high power continuous-wave laser beam is focused at a point in an air flow field and Rayleigh scattered light is collected and fiber-optically transmitted to the spectral analysis and detection equipment. The spectrum of the light, which contains information about the temperature and velocity of the flow, is analyzed using a Fabry-Perot interferometer. Photomultiplier tubes operated in the photon counting mode allow high frequency sampling of the circular interference pattern to provide time-resolved flow property measurements. An acoustically driven nozzle flow is studied to validate velocity fluctuation measurements, and an asymmetric oscillating counterflow with unequal enthalpies is studied to validate the measurement of temperature fluctuations. Velocity fluctuations are compared with constant temperature anemometry measurements and temperature fluctuations are compared with constant current anemometry measurements at the same locations. Time-series and power spectra of the temperature and velocity measurements are presented. A numerical simulation of the light scattering and detection process was developed and compared with experimental data for future use as an experiment design tool.

  11. Light scattering by a thin wire with a surface-plasmon resonance: Bifurcations of the Poynting vector field

    SciTech Connect

    Luk'yanchuk, B. S.; Ternovsky, V.

    2006-06-15

    We analyze the energy flow during the scattering of a plane wave by a small homogeneous cylinder in the vicinity of surface-plasmon resonance, where {epsilon}{sup '}=Re {epsilon}=-1 ({epsilon} stands for permittivity). For the case of small dissipation, {epsilon}{sup ''}=Im {epsilon}<<1, this scattering can strongly deviate from the classical dipole approximation (Rayleigh scattering). In certain specified cases, the Rayleigh scattering is replaced with an anomalous light scattering regardless the wire smallness. The phenomenon is based on interplay of the usual dissipative and radiative damping, where the latter is related to inverse transformation of localized resonant plasmons into scattered light. The anomalous light scattering possesses a variety of unusual features, such as an inverse hierarchy of optical resonances and a complicated near-field structure, which may include optical vortexes, optical whirlpools, and other peculiarities in nanoscale area.

  12. Highly sensitive detection of chromium (III) ions by resonance Rayleigh scattering enhanced by gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Min; Cai, Huai-Hong; Yang, Fen; Lin, Dewen; Yang, Pei-Hui; Cai, Jiye

    2014-01-01

    Simple and sensitive determination of chromium (III) ions (Cr3+) has potential applications for detecting trace contamination in environment. Here, the assay is based on the enhancement of resonance Rayleigh scattering (RRS) by Cr3+-induced aggregation of citrate-capped gold nanoparticles (AuNPs). Transmission electron microscopy (TEM) and UV-vis absorption spectroscopy were employed to characterize the nanostructures and spectroscopic properties of the Cr3+-AuNP system. The experiment conditions, such as reaction time, pH value, salt concentration and interfering ions, were investigated. The combination of signal amplification of Cr3+-citrate chelation with high sensitivity of RRS technique allow a selective assay of Cr3+ ions with a detection limit of up to 1.0 pM. The overall assay can be carried out at room temperature within only twenty minutes, making it suitable for high-throughput routine applications in environment and food samples.

  13. Molecular Rayleigh Scattering Techniques Developed for Measuring Gas Flow Velocity, Density, Temperature, and Turbulence

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Seasholtz, Richard G.; Elam, Kristie A.; Panda, Jayanta

    2005-01-01

    Nonintrusive optical point-wise measurement techniques utilizing the principles of molecular Rayleigh scattering have been developed at the NASA Glenn Research Center to obtain time-averaged information about gas velocity, density, temperature, and turbulence, or dynamic information about gas velocity and density in unseeded flows. These techniques enable measurements that are necessary for validating computational fluid dynamics (CFD) and computational aeroacoustic (CAA) codes. Dynamic measurements allow the calculation of power spectra for the various flow properties. This type of information is currently being used in jet noise studies, correlating sound pressure fluctuations with velocity and density fluctuations to determine noise sources in jets. These nonintrusive techniques are particularly useful in supersonic flows, where seeding the flow with particles is not an option, and where the environment is too harsh for hot-wire measurements.

  14. A nanogold resonance Rayleigh scattering method for determination of trace As based on the hydride nanoreaction.

    PubMed

    Jiang, Caina; Chen, Chunqiang; Lu, Zujun; Liu, Qingye; Tang, Meiling; Liang, Aihui; Jiang, Zhiliang

    2015-09-01

    In H2 SO4 solution, As(III) was reduced to arsine (AsH3 ) by NaBH4 , and was absorbed in HAuCl4 solution to form nanogold particles (NGs) that exhibited a resonance Rayleigh scattering (RRS) effect at 370 nm. Under the selected conditions, when the As(III) concentration increased the RRS peak also increased due to the formation of more NGs. There was a linear correlation between RRS intensity and As(III) concentration in the range 6-1000 ng/mL, with a detection limit of 3 ng/mL. This new hydride generation-nanogold reaction RRS (HG-NG RRS) method was applied to determine trace amounts of As in milk samples, with satisfactory results.

  15. A new resonance Rayleigh scattering spectral method for determination of O3 with victoria blue B

    NASA Astrophysics Data System (ADS)

    Wen, Guiqing; Yang, Duo; Jiang, Zhiliang

    2014-01-01

    Ozone (O3) could be absorbed by boric acid-potassium iodide (BKI) absorbent solution to produce tri-iodine ion (I3-) that react with victoria blue B (VBB) to form the associated particle (VBB-I3)n and exhibited a strong resonance Rayleigh scattering (RRS) peak at 722 nm. Under the chosen conditions, the RRS peak intensity was linear with O3 concentration in the range of 0.2-50 μmol/L, with a linear regression equation of ΔI722 = 17.9c - 45.4 and detection limit of 0.057 μmol/L. Accordingly, a simple, rapid and sensitive RRS spectral method was set up for determination of trace O3 in air, with satisfactory results.

  16. Slow-light effect via Rayleigh anomaly and the effect of finite gratings.

    PubMed

    Kim, Kyoung-Youm; Chong, Xinyuan; Ren, Fanghui; Wang, Alan X

    2015-11-15

    In this Letter, we investigate the slow-light effect of subwavelength diffraction gratings via the Rayleigh anomaly using a fully analytical approach without needing to consider specific grating structures. Our results show that the local group velocity of the transmitted light can be significantly reduced due to the optical vortex, which can inspire a new mechanism to enhance light-matter interactions for optical sensing and photodetection. However, the slow-light effect will diminish as the transmitted light propagates farther from the grating surface, and the slowdown factor decreases as the grating size shrinks.

  17. Ultrasensitive detection of target analyte-induced aggregation of gold nanoparticles using laser-induced nanoparticle Rayleigh scattering.

    PubMed

    Lin, Jia-Hui; Tseng, Wei-Lung

    2015-01-01

    Detection of salt- and analyte-induced aggregation of gold nanoparticles (AuNPs) mostly relies on costly and bulky analytical instruments. To response this drawback, a portable, miniaturized, sensitive, and cost-effective detection technique is urgently required for rapid field detection and monitoring of target analyte via the use of AuNP-based sensor. This study combined a miniaturized spectrometer with a 532-nm laser to develop a laser-induced Rayleigh scattering technique, allowing the sensitive and selective detection of Rayleigh scattering from the aggregated AuNPs. Three AuNP-based sensing systems, including salt-, thiol- and metal ion-induced aggregation of the AuNPs, were performed to examine the sensitivity of laser-induced Rayleigh scattering technique. Salt-, thiol-, and metal ion-promoted NP aggregation were exemplified by the use of aptamer-adsorbed, fluorosurfactant-stabilized, and gallic acid-capped AuNPs for probing K(+), S-adenosylhomocysteine hydrolase-induced hydrolysis of S-adenosylhomocysteine, and Pb(2+), in sequence. Compared to the reported methods for monitoring the aggregated AuNPs, the proposed system provided distinct advantages of sensitivity. Laser-induced Rayleigh scattering technique was improved to be convenient, cheap, and portable by replacing a diode laser and a miniaturized spectrometer with a laser pointer and a smart-phone. Using this smart-phone-based detection platform, we can determine whether or not the Pb(2+) concentration exceed the maximum allowable level of Pb(2+) in drinking water.

  18. Light Scattering by Fractal Dust Aggregates. I. Angular Dependence of Scattering

    NASA Astrophysics Data System (ADS)

    Tazaki, Ryo; Tanaka, Hidekazu; Okuzumi, Satoshi; Kataoka, Akimasa; Nomura, Hideko

    2016-06-01

    In protoplanetary disks, micron-sized dust grains coagulate to form highly porous dust aggregates. Because the optical properties of these aggregates are not completely understood, it is important to investigate how porous dust aggregates scatter light. In this study, the light scattering properties of porous dust aggregates were calculated using a rigorous method, the T-matrix method, and the results were then compared with those obtained using the Rayleigh-Gans-Debye (RGD) theory and Mie theory with the effective medium approximation (EMT). The RGD theory is applicable to moderately large aggregates made of nearly transparent monomers. This study considered two types of porous dust aggregates—ballistic cluster-cluster agglomerates (BCCAs) and ballistic particle-cluster agglomerates. First, the angular dependence of the scattered intensity was shown to reflect the hierarchical structure of dust aggregates; the large-scale structure of the aggregates is responsible for the intensity at small scattering angles, and their small-scale structure determines the intensity at large scattering angles. Second, it was determined that the EMT underestimates the backward scattering intensity by multiple orders of magnitude, especially in BCCAs, because the EMT averages the structure within the size of the aggregates. It was concluded that the RGD theory is a very useful method for calculating the optical properties of BCCAs.

  19. Light scattering of degenerate fermions

    NASA Astrophysics Data System (ADS)

    Aubin, S.; Leblanc, L. J.; Myrskog, S.; Extavour, M. H. T.; McKay, D.; Stummer, A.; Thywissen, J. H.

    2006-05-01

    We report on progress in measuring the suppression of resonant light scattering in a gas of degenerate fermions. A gas of trapped degenerate fermions is expected to exhibit narrower optical linewidths and longer excited state lifetimes than single atoms when the Fermi energy is larger than the photon recoil energy [1-3]. In this case, the number of available states into which a scattered atom can recoil is significantly reduced due to the filling of the Fermi sea. We produce a degenerate gas of 4x10^4 ultra-cold fermionic ^40K atoms by sympathetic cooling with bosonic ^87Rb in a micro-magnetic chip trap. The atoms can then be loaded into a tight dipole trap just above the surface of the chip and probed with a near resonance laser pulse. [1] Th. Busch, J. R. Anglin, J. I. Cirac, and P. Zoller, Europhys. Lett. 44, 1 (1998). [2] B. DeMarco and D. S. Jin, Phys. Rev. A 58, R4267 (1998). [3] J. Javanainen and J. Ruostekosky, Phys. Rev. A 52, 3033 (1995). Work supported by NSERC, CFI, OIT, Research Corporation, and PRO.

  20. Scattering theory of stochastic electromagnetic light waves.

    PubMed

    Wang, Tao; Zhao, Daomu

    2010-07-15

    We generalize scattering theory to stochastic electromagnetic light waves. It is shown that when a stochastic electromagnetic light wave is scattered from a medium, the properties of the scattered field can be characterized by a 3 x 3 cross-spectral density matrix. An example of scattering of a spatially coherent electromagnetic light wave from a deterministic medium is discussed. Some interesting phenomena emerge, including the changes of the spectral degree of coherence and of the spectral degree of polarization of the scattered field.

  1. Biological cell classification by multiangle light scattering

    DOEpatents

    Salzman, G.C.; Crowell, J.M.; Mullaney, P.F.

    1975-06-03

    The specification is directed to an apparatus and method for detecting light scattering from a biological cell. Light, preferably from a coherent source of radiation, intercepts an individual biological cell in a stream of cells passing through the beam. Light scattered from the cell is detected at a selected number of angles between 0 and 90/sup 0/ to the longitudinal axis of the beam with a circular array of light responsive elements which produce signals representative of the intensity of light incident thereon. Signals from the elements are processed to determine the light-scattering pattern of the cell and therefrom its identity.

  2. Brillouin light scattering from surface acoustic waves in a subwavelength-diameter optical fibre

    PubMed Central

    Beugnot, Jean-Charles; Lebrun, Sylvie; Pauliat, Gilles; Maillotte, Hervé; Laude, Vincent; Sylvestre, Thibaut

    2014-01-01

    Brillouin scattering in optical fibres is a fundamental interaction between light and sound with important implications ranging from optical sensors to slow and fast light. In usual optical fibres, light both excites and feels shear and longitudinal bulk elastic waves, giving rise to forward-guided acoustic wave Brillouin scattering and backward-stimulated Brillouin scattering. In a subwavelength-diameter optical fibre, the situation changes dramatically, as we here report with the first experimental observation of Brillouin light scattering from surface acoustic waves. These Rayleigh-type surface waves travel the wire surface at a specific velocity of 3,400 m s−1 and backscatter the light with a Doppler shift of about 6 GHz. As these acoustic resonances are sensitive to surface defects or features, surface acoustic wave Brillouin scattering opens new opportunities for various sensing applications, but also in other domains such as microwave photonics and nonlinear plasmonics. PMID:25341638

  3. Rayleigh Light Scattering for Concentration Measurements in Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Pitts, William M.

    1996-01-01

    Despite intensive research over a number of years, an understanding of scalar mixing in turbulent flows remains elusive. An understanding is required because turbulent mixing has a pivotal role in a wide variety of natural and technologically important processes. As an example, the mixing and transport of pollutants in the atmosphere and in bodies of water are often dependent on turbulent mixing processes. Turbulent mixing is also central to turbulent combustion which underlies most hydrocarbon energy use in modern societies as well as in unwanted fire behavior. Development of models for combusting flows is therefore crucial, however, an understanding of scalar mixing is required before useful models of turbulent mixing and, ultimately, turbulent combustion can be developed. An important subset of turbulent flows is axisymmetric turbulent jets and plumes because they are relatively simple to generate, and because the provide an appropriate test bed for the development of general theories of turbulent mixing which can be applied to more complex geometries and flows. This paper focuses on a number of experimental techniques which have been developed at the National Institute of Standards and Development for measuring concentration in binary axisymmetric turbulent jets. In order to demonstrate the value of these diagnostics, some of the more important results from earlier and on-going investigations are summarized. Topics addressed include the similarity behavior of variable density axisymmetric jets, the behavior of absolutely unstable axisymmetric helium jets, and the role of large scale structures and scalar dissipation in these flows.

  4. Slow-light effect via Rayleigh anomaly and the effect of finite gratings

    PubMed Central

    Kim, Kyoung-Youm; Chong, Xinyuan; Ren, Fanghui; Wang, Alan X.

    2016-01-01

    In this Letter, we investigate the slow-light effect of sub-wavelength diffraction gratings via the Rayleigh anomaly using a fully analytical approach without needing to consider specific grating structures. Our results show that the local group velocity of the transmitted light can be significantly reduced due to the optical vortex, which can inspire a new mechanism to enhance light–matter interactions for optical sensing and photodetection. However, the slow-light effect will diminish as the transmitted light propagates farther from the grating surface, and the slowdown factor decreases as the grating size shrinks. PMID:26565869

  5. Hyper-Rayleigh scattering and hyper-Raman scattering of dye-adsorbed silver nanoparticles induced by a focused continuous-wave near-infrared laser

    SciTech Connect

    Itoh, Tamitake; Ozaki, Yukihiro; Yoshikawa, Hiroyuki; Ihama, Takashi; Masuhara, Hiroshi

    2006-02-20

    We report that hyper-Rayleigh scattering, surface-enhanced hyper-Raman scattering, and two-photon excited luminescence occur intermittently by focusing a continuous-wave near-infrared (cw-NIR) laser into a colloidal silver solution including rhodamine 6G (R6G) and sodium chloride (NaCl). On the other hand, continuous hyper-Rayleigh scattering is observed from colloidal silver free from R6G and NaCl, demonstrating that hyper-Raman scattering and two-photon excited luminescence are attributed to R6G and their intermittent features are dependent on the colloidal dispersion. These results suggest that the cw-NIR laser has three roles; the source of the nonlinear response, optical trapping of nanoparticles, and making nanoparticle aggregates possessing the high activity for the nonlinear response.

  6. Highly efficient and two-photon excited stimulated Rayleigh-Bragg scattering in organic solutions

    SciTech Connect

    He, Guang S. Prasad, Paras N.; Kannan, Ramamurthi; Tan, Loon-Seng

    2015-07-21

    The properties of backward stimulated Rayleigh-Bragg scattering (SRBS) in three highly two-photon active AF-chromophores solutions in tetrahydrofuran (THF) have been investigated using 816-nm and 8-ns pump laser beam. The nonlinear reflectivity R, spectral structure, temporal behavior, and phase-conjugation capability of the backward SRBS output have been measured, respectively. Under the same experimental condition, the pump threshold for SRBS in three solution samples can be significantly (∼one order of magnitude) lower than that for stimulated Brillouin scattering (SBS) in the pure solvent (THF). With the optimized concentration value and at a moderate pump energy (∼1.5 mJ) level, the measured nonlinear reflectivity was R ≥ 35% for the 2 cm-long solution sample, while for the SBS from a pure solvent sample of the same length was R ≈ 4.7%. The peculiar features of very low pump threshold, no spectral shift, tolerant pump spectral linewidth requirement (≤1 cm{sup −1}), and phase-conjugation capability are favorable for those nonlinear photonics applications, such as highly efficiency phase-conjugation reflectors for high-brightness laser oscillator/amplifier systems, special imaging through turbid medium, self-adaptive remote optical sensing, as well as for optical rangefinder and lidar systems.

  7. Violation of a Bell-like inequality by a combination of Rayleigh scattering with a Mach-Zehnder setup

    NASA Astrophysics Data System (ADS)

    Rother, Tom

    2016-07-01

    In this paper I propose a classical optics experiment that results in a maximum violation of a Bell-like inequality. The first part is concerned with the Bell-like inequality (the so-called CHSH-inequality) itself. Its importance and its maximum violation in Quantum Mechanics (QM) are discussed in detail by employing an abstract probability state concept in a 4-dim. but classical event space. A T-matrix that represents the integral part of a corresponding Green's function as well as a statistical operator that contains a negative quasi-probability can be related to the corresponding quantum mechanical experiment. It is demonstrated that the derivation and usage of the T-matrix and the Green's function is equivalent to what is known from classical scattering theory. It is shown moreover that the negative quasi-probability of the statistical operator may be interpreted as a sink of probabilities related to two single events of the considered 4-dim. event space. A necessary condition for the violation of the CHSH-inequality is derived and discussed afterwards. In the second part of this paper I discuss a modification of the 4-dim. event space considered in the first part. It is shown that a combination of conventional Rayleigh scattering with a Mach-Zehnder setup would be able to put this modification into practice. Thus it becomes possible to achieve a maximum violation of the CHSH-inequality, if formulated in terms of intensities, on a pure classical way. The combination of classical light scattering with correlation experiments such as proposed in this paper may open new ways to study and to use the violation of Bell-like inequalities in modern optics.

  8. Angle-Resolved Second-Harmonic Light Scattering from Colloidal Particles

    NASA Astrophysics Data System (ADS)

    Yang, N.; Angerer, W. E.; Yodh, A. G.

    2001-09-01

    We report angle-resolved second-harmonic generation (SHG) measurements from suspensions of centrosymmetric micron-size polystyrene spheres with surface-adsorbed dye (malachite green). The second-harmonic scattering profiles differ qualitatively from linear light scattering profiles of the same particles. We investigated these radiation patterns using several polarization configurations and particle diameters. We introduce a simple Rayleigh-Gans-Debye model to account for the SHG scattering anisotropy. The model compares favorably with our experimental data. Our measurements suggest scattering anisotropy may be used to isolate particle nonlinear optics from other bulk nonlinear optical effects in suspension.

  9. Angle-Resolved Second-Harmonic Light Scattering from Colloidal Particles

    SciTech Connect

    Yang, N.; Angerer, W. E.; Yodh, A. G.

    2001-09-03

    We report angle-resolved second-harmonic generation (SHG) measurements from suspensions of centrosymmetric micron-size polystyrene spheres with surface-adsorbed dye (malachite green). The second-harmonic scattering profiles differ qualitatively from linear light scattering profiles of the same particles. We investigated these radiation patterns using several polarization configurations and particle diameters. We introduce a simple Rayleigh-Gans-Debye model to account for the SHG scattering anisotropy. The model compares favorably with our experimental data. Our measurements suggest scattering anisotropy may be used to isolate particle nonlinear optics from other bulk nonlinear optical effects in suspension.

  10. Absolute Rayleigh scattering cross sections of gases and freons of stratospheric interest in the visible and ultraviolet regions

    NASA Technical Reports Server (NTRS)

    SHARDANAND; Rao, A. D. P.

    1977-01-01

    The laboratory measurements of absolute Rayleigh scattering cross sections as a function wavelength are reported for gas molecules He, Ne, Ar, N2, H2, O2, CO2, CH4 and for vapors of most commonly used freons CCl2F2, CBrF3, CF4, and CHClf2. These cross sections are determined from the measurements of photon scattering at an angle of 54 deg 44 min which yield the absolute values independent of the value of normal depolarization ratios. The present results show that in the spectral range 6943-3638A deg, the values of the Rayleigh scattering cross section can be extrapolated from one wavelength to the other using 1/lambda (4) law without knowing the values of the polarizabilities. However, such an extrapolation can not be done in the region of shorter wavelengths.

  11. Theory of Light Scattering in Axion Electrodynamics

    NASA Astrophysics Data System (ADS)

    Ochiai, Tetsuyuki

    2012-09-01

    Taking account of the axion term in the Maxwell Lagrangian, we present a rigorous theory of light scattering in piecewise-constant axion fields. In particular, we focus on axionic substances with confined and/or curved geometries, and the scattering matrices of an axionic slab, cylinder, and sphere are derived analytically. The axion term generates a surface current with off-diagonal optical conductivity, giving rise to a new type of photospin--orbit interaction. As a result, various novel light-scattering phenomena can take place. We demonstrate enhanced Faraday rotation, parity-violating light scattering, and strong perturbation of dipole radiation.

  12. [Resonance Rayleigh scattering determination of trace tobramycin using aptamer-modified nanogold as probe ].

    PubMed

    Ma, Lu; Wen, Gui-Qing; Liu, Qing-Ye; Liang, Ai-Hui; Jiang, Zhi-Liang

    2014-09-01

    Nanogold (NG) was prepared using NaBH4 reduction of HAuCl4. The NG was modified by the tobramycin-aptamer to obtain a stable Apt-NG probe for tobramycin. The three aptamers containing 15, 21 and 27 bases were examined, and results showed that the aptamer with 21 bases was best and was chosen for use. In pH 6. 8 PBS buffer solution and in the presence of NaCl, the Apt-GN probes were not aggregated. When tobramycin was added, it reacted with the Apt of Apt-NG probe to form a very stable Apt-Tbc complex and released NGs that were aggregated into big particles under the action of NaCl with three resonance Rayleigh scattering peaks at 285, 368 and 525 nm respectively. The resonance Rayleigh scattering peak increased at 368 nm due to the formation of big NG particles from the probe. The effect of pH buffer solution, its volume, and Apt-GN probe concentration on the ΔI value was considered. A 200 μL pH 6. 8 PBS buffer solution and 19. 1 nmol · L(-3) Apt-GN, giving max ΔI value, were chosen for use. Under the chosen conditions, the increased resonance Rayleigh scattering intensity ΔI368 nm was linear with Tbc concentration in the range of 1.9-58.3 ng mL(-3), with a regress equation of ΔI = 35.3c-23 and a detection limit of 0.8 ng · mL(-3) Tbc. A 10.0, 20.0 and 30.0 ng mL-3 Tbc was determined five times respectively, and the relative standard deviations were 6.8%, 5.0% and 4.4%. The influence of some foreign substances was examined on the determination of 38.9 ng · mL(-3) Tbc, within ±10% related error. Results showed that a 80 times of Zn2+, 40 times of L-glutamic acid, Cu2+, Mg2+ and Ca2+, 20 times of glucose and terramycin, 10 times of L-phenylalanine and glycin, 2 times of L-aspartic acid, and 6 times of bovine serum albumin (BSA) and human serum albumin (HSA) do not interfere with the RRS determination of Tbc. The results showed that this aptamer-nanogold RRS method is of good selectivity. Tbc in real sample was analyzed, and the analytical result was in

  13. Comparison of Coincident Rayleigh-Scatter and Sodium Resonance Lidar Temperature Measurements from the Mesosphere-Lower-Thermosphere Region

    NASA Astrophysics Data System (ADS)

    Sox, L.; Wickwar, V. B.; Yuan, T.; Criddle, N.

    2015-12-01

    There are relatively few instruments that have the capabilities to make near continuous measurements of the mesosphere-lower-thermosphere (MLT) region. Rayleigh scatter and resonance lidars, particularly sodium resonance lidar, have been the two dominant ground-based techniques for acquiring mesosphere and MLT vertical temperature profiles, respectively, for more than two decades. With these measurements, the dynamics (gravity waves, tides) and long-term temperature trends (upper atmosphere cooling) of the MLT region can be studied. The Utah State University (USU; 41.7º N, 111.8º W) campus hosts a unique upper atmospheric observatory which houses both a high-power, large-aperture Rayleigh lidar and a sodium resonance Doppler lidar. For the first time, we will present coordinated, night-time averaged temperatures, overlapping in observational range (80-110 km), from the two lidars. This overlap has been achieved through the relocation of the sodium lidar from Colorado State University to USU's campus and through upgrades to the existing USU Rayleigh lidar which elevated its observational range from 45-90 km to 70-115 km. The comparison of the two sets of temperature measurements is important because the two lidar techniques derive temperature profiles using different scattering processes and analysis methods. Furthermore, previous climatological comparisons, between Rayleigh and sodium lidar, [Argall and Sica, 2007] have suggested that significant temperature differences can occur. This comparison aims to explore possible temperature effects from the differences in the two measurement techniques.

  14. Bidirectional scattering of light from tree leaves

    NASA Technical Reports Server (NTRS)

    Brakke, Thomas W.; Smith, James A.; Harnden, Joann M.

    1989-01-01

    A laboratory goniometer consisting of an He-Ne laser (632.8 nm), vertical leaf holder, and silicon photovoltaic detector was used to measure the bidirectional scattering (both transmittance and reflectance) of red oak and red maple. The illumination angles were 0, 30, and 60 deg, and the scattering was recorded approximately every 10 deg in the principal plane. The scattering profiles obtained show the non-Lambertian characteristics of the scattering, particularly for the off-nadir illumination directions. The transmitted light was more isotropic than the reflected light.

  15. Resonance Rayleigh scattering method for highly sensitive detection of chitosan using aniline blue as probe.

    PubMed

    Zhang, Weiai; Ma, Caijuan; Su, Zhengquan; Bai, Yan

    2016-11-01

    This paper describes a highly sensitive and accurate approach using aniline blue (AB) (water soluble) as a probe to determine chitosan (CTS) through Resonance Rayleigh scattering (RRS). Under optimum experimental conditions, the intensities of RRS were linearly proportional to the concentration of CTS in the range from 0.01 to 3.5μg/mL, and the limit of detection (LOD) was 6.94ng/mL. Therefore, a new and highly sensitive method based on RRS for the determination of CTS has been developed. Furthermore, the effect of molecular weight of CTS and the effect of the degree of deacetylation of CTS on the accurate quantification of CTS was studied. The experimental data was analyzed by linear regression analysis, which indicated that the molecular weight and the degree of deacetylation of CTS had no statistical significance and this method could be used to determine CTS accurately. Meanwhile, this assay was applied for CTS determination in health products with satisfactory results.

  16. Rayleigh Scattering Density Measurements, Cluster Theory, and Nucleation Calculations at Mach 10

    NASA Technical Reports Server (NTRS)

    Balla, R. Jeffrey; Everhart, Joel L.

    2012-01-01

    In an exploratory investigation, quantitative unclustered laser Rayleigh scattering measurements of density were performed in the air in the NASA Langley Research Center's 31 in. Mach 10 wind tunnel. A review of 20 previous years of data in supersonic and Mach 6 hypersonic flows is presented where clustered signals typically overwhelmed molecular signals. A review of nucleation theory and accompanying nucleation calculations are also provided to interpret the current observed lack of clustering. Data were acquired at a fixed stagnation temperature near 990Kat five stagnation pressures spanning 2.41 to 10.0 MPa (350 to 1454 psi) using a pulsed argon fluoride excimer laser and double-intensified charge-coupled device camera. Data averaged over 371 images and 210 pixels along a 36.7mmline measured freestream densities that agree with computed isentropic-expansion densities to less than 2% and less than 6% at the highest and lowest densities, respectively. Cluster-free Mach 10 results are compared with previous clustered Mach 6 and condensation-free Mach 14 results. Evidence is presented indicating vibrationally excited oxygen and nitrogen molecules are absorbed as the clusters form, release their excess energy, and inhibit or possibly reverse the clustering process. Implications for delaying clustering and condensation onset in hypersonic and hypervelocity facilities are discussed.

  17. A silver nanorod resonance rayleigh scattering-energy transfer analytical platform for trace tea polyphenols.

    PubMed

    Liang, Aihui; Wang, Yaohui; Wen, Guiqing; Zhang, Xinghui; Luo, Yanghe; Jiang, Zhiliang

    2016-04-15

    The stable silver nanorod (AgNR) sol in red was prepared by the two-step procedure of NaBH4-H2O2 and citrate heating reduction, and it exhibited a strong resonance Rayleigh scattering (RRS) peak at 346 nm. In pH 3.8 HAc-NaAc buffer solution, tea polyphenols (TP) reacted with ammonium molybdate (AM) to form yellow organic molybdate (OM) as receptor that was closed to the donor of AgNR, the RRS energy transfer (RRS-ET) takes place, owing to the overlapping between the AgNR RRS spectra and OM absorption spectra. When TP concentration increased, the RRS intensity decreased due to the RRS-ET increasing. So, a simple and sensitive AgNR surface plasmon RRS-ET analytical platform was fabricated to detect trace TP in the range of 0.05-0.85 μg/mL, with a detection limit of 0.03 μg/mL TP. The TP in tea samples was analyzed by this RRS-ET analysis platform, with satisfactory results.

  18. Resonance Rayleigh scattering method for highly sensitive detection of chitosan using aniline blue as probe

    NASA Astrophysics Data System (ADS)

    Zhang, Weiai; Ma, Caijuan; Su, Zhengquan; Bai, Yan

    2016-11-01

    This paper describes a highly sensitive and accurate approach using aniline blue (AB) (water soluble) as a probe to determine chitosan (CTS) through Resonance Rayleigh scattering (RRS). Under optimum experimental conditions, the intensities of RRS were linearly proportional to the concentration of CTS in the range from 0.01 to 3.5 μg/mL, and the limit of detection (LOD) was 6.94 ng/mL. Therefore, a new and highly sensitive method based on RRS for the determination of CTS has been developed. Furthermore, the effect of molecular weight of CTS and the effect of the degree of deacetylation of CTS on the accurate quantification of CTS was studied. The experimental data was analyzed by linear regression analysis, which indicated that the molecular weight and the degree of deacetylation of CTS had no statistical significance and this method could be used to determine CTS accurately. Meanwhile, this assay was applied for CTS determination in health products with satisfactory results.

  19. Resonance Rayleigh scattering method for the determination of cationic surfactants with chromium(VI)-iodide system.

    PubMed

    Liu, Shaopu; Shi, Yan; Liu, Zhongfang; Luo, Hongqun; Kong, Ling

    2006-05-01

    A method for detecting and identifying cationic surfactant in some chemical samples for daily use that include Head & Shoulder Ampoule and Slek Shower Lotion has been developed. In an acid medium, chromium(VI) oxidizes I(-) to produce I(2), I(2) binds excess of I(-) to form I(3)(-), and I(3)(-) can further react with a cationic surfactant (CS) (such as cetyldimethyl benzylammonium chloride (CDBAC), Zephiramine (Zeph), cetylpyridinium bromide (CPB), tetradecyl pyridinium bromide (TPB) and cetyltrimethylammonium bromide (CTAB)) to form ion-association complexes [CS][I(3)]. This results in a significant enhancement of resonance Rayleigh scattering (RRS) and appearance of new RRS spectra. The RRS spectral characteristics of the ion-association complexes, the influencing factors and the optimum conditions of the reactions have been investigated. The intensities of RRS are directly proportional to the concentration of CS. CS in samples are collected using a treated anion exchange column and subsequently complexed by I(3)(-); then the RRS intensities of CS complex are determined at 495 nm. The reactions have high sensitivities, and their detection limits are 7.05 - 9.62 ng/mL for different CS. The effects of foreign substances are investigated and the results show that the method has good selectivity.

  20. Determination of thiram using gold nanoparticles and Resonance Rayleigh scattering method.

    PubMed

    Parham, Hooshang; Pourreza, Nahid; Marahel, Farzaneh

    2015-08-15

    A sensitive, simple and novel method was developed to determine thiram fungicide in water and plant samples. This method was based on the interaction between gold nanoparticles (AuNPs) and thiram fungicide followed by increasing of the Resonance Rayleigh scattering (RRS) intensity of nanoparticles. The change in RRS intensity (∆IRRS) was linearly correlated to the concentration of thiram over the range of 1.0-200.0µgL(-1). Thiram can be measured in a short time (4min) without any complicated or time-consuming sample pretreatment process. Parameters that affect the RRS intensities such as pH, concentration of AuNPs, standing time, electrolyte concentration, and coexisting substances were systematically investigated and optimized. Interference tests showed that the developed method has a very good selectivity and could be used conveniently for the determination of thiram. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 1.0µg L(-1), respectively. Relative standard deviations (RSD) for 20.0 and 80.0µg L(-1) of thiram were 3.0 and 1.1, respectively. Possible mechanisms for the RRS changes of AuNPs in the presence of thiram were discussed and the method was successfully applied for the analysis of spiked real water samples and fresh plant samples such as tomato and cucumber.

  1. Characterization of the nonlinear optical properties of nanocrystals by Hyper Rayleigh Scattering

    PubMed Central

    2013-01-01

    Background Harmonic Nanoparticles are a new family of exogenous markers for multiphoton imaging exerting optical contrast by second harmonic (SH) generation. In this tutorial, we present the application of Hyper-Rayleigh Scattering (HRS) for a quantitative assessment of the nonlinear optical properties of these particles and discuss the underlying theory and some crucial experimental aspects. Methods The second harmonic properties of BaTiO3, KNbO3, KiTiOPO4 (KTP), LiNbO3 and ZnO nanocrystals (NCs) are investigated by HRS measurements after careful preparation and characterization of colloidal suspensions. Results A detailed analysis of the experimental results is presented with emphasis on the theoretical background and on the influence of some experimental parameters including the accurate determination of the nanocrystal size and concentration. The SH generation efficiency and averaged nonlinear optical coefficients are then derived and compared for six different types of NCs. Conclusions After preparation of colloidal NC suspensions and careful examination of their size, concentration and possible aggregation state, HRS appears as a valuable tool to quantitatively assess the SH efficiency of noncentrosymmetric NCs. All the investigated nanomaterials show high SH conversion efficiencies, demonstrating a good potential for bio-labelling applications. PMID:24564891

  2. A simple and rapid resonance Rayleigh scattering method for detection of indigo carmine in soft drink.

    PubMed

    Li, Qin; Yang, Jidong; Tan, Xuanping; Zhang, Zhan; Hu, Xiaomei; Yang, Menghuan

    2016-08-01

    A novel method that uses acridine orange (AO) to detect indigo carmine (IC) in soft drinks was developed. The method is highly sensitive and is based on a resonance Rayleigh scattering (RRS) technique. In Britton-Robinson (BR) buffer solution, pH 4.3, the weak RRS intensity of AO was greatly enhanced by the addition of IC, with the maximum peak located at 332 nm. Under optimum conditions, it was found that the enhanced RRS intensity was proportional to the concentration of IC over a range of 2-32 × 10(-6)  mol/L. A low detection limit of 2.4 × 10(-8)  mol/L was achieved. The sensitivity and selectivity of the method are high enough to permit the determination of trace amounts of IC without any significant interference from high levels of other components such as common anions and other amino acids. Finally, the concentration of IC in three different soft drinks was determined with satisfactory results. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26791156

  3. Verification of radiative transfer results by inserting them into the RTE: A demonstration for Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Hollstein, André

    2012-10-01

    The verification of a new or updated radiative transfer model (RTM) is one of the important steps in its development; this is usually achieved by comparisons with real measurements or published tables of generally accepted radiative transfer results. If such tables do not exist, verification becomes more complicated and an external review of the implementation is often unpractical due to the sheer amount and complexity of the code. The presented verification approach is to “simply” insert results of radiative transfer (RT) calculations into the radiative transfer equation (RTE). The evaluation of the RTE consists of numerically calculating partial derivatives and integrals, which is much simpler to implement than a solution of the RTE. Presented is a demonstration of this approach for a case of Rayleigh scattering in a plane parallel atmosphere, which showed only very small deviation from the radiative transfer equation.This approach has two key benefits. First, its implementation into a high level computer language can be very short (≈60 lines in MATHEMATICA) and clear compared to a full RTM; and such code is much more easy to review. Second, this approach can be easily extended to cases where no other independent RT implementation is available for validation. The proposed implementation and data are provided with this paper.

  4. Resonance Rayleigh scattering study of interaction of heparin with some cationic surfactants and their analytical application

    NASA Astrophysics Data System (ADS)

    Liu, Shao Pu; Luo, Hong Qun; Xu, Hong; Li, Nian Bing

    2005-03-01

    Binding of heparin with a cationic surfactant such as cetyldimethyl benzylammonium chloride (CDBAC), tetradecyldimethyl benzylammonium chloride (Zeph), cetylpyridinium bromide (CPB), tetradecane pyridinium bromide (TPB) and cetyltrimethylammonium bromide (CTAB) in a near-neutral medium can result in a significant enhancement of resonance Rayleigh scattering (RRS) intensities. The results showed that the reaction conditions and RRS spectral characteristics of these reactions are similar, but their sensitivities are obviously different. Among them, the sensitivity of CDBAC with an aryl and large molecular weight is the highest, while that of CTAB without aryl and with small molecular weight is the lowest. The detection limit for heparin of the former is 11 ng ml -1 while that of the latter is 33 ng ml -1. The method has better selectivity and was applied to the determination of trace amounts of heparin in sodium heparin injection samples with satisfactory results. Furthermore, it is discovered that the RRS intensity is related to the structure and molecular weight of the cationic surfactant.

  5. Pulsed laser Rayleigh scattering diagnostic for hydrogen/oxygen rocket exit plane flowfield velocimetry

    NASA Technical Reports Server (NTRS)

    Zupanc, Frank J.

    1993-01-01

    A Doppler-resolved, pulsed laser Rayleigh scattering diagnostic has been developed to obtain local flowfield velocity measurements at the exit plane of a low thrust hydrogen/oxygen rocket engine operating in a high-altitude test facility. Fiberoptic signal collection was employed to obtain the forescatter and backscatter Doppler shifts necessary to resolve the axial and radial velocity components. A radial profile was obtained by traversing the collection probes along the beam path at the nozzle exit. The results are compared with theoretical predictions from a full Navier-Stokes model (RK/RPLUS). Significant discrepancies between the measured and predicted axial velocity profiles are observed, in terms of both magnitude and character. Radial velocity measurements exhibit excellent agreement with predictions near the centerline but show some departure off-axis. The discrepancies between theory and experiment are potentially the result of enhanced mixing between the core and fuel-film region beyond that predicted, and/or flow stratification between the hydrogen and oxygen injected into the central core region.

  6. Hydride generation-resonance Rayleigh scattering and SERS spectral determination of trace Bi

    NASA Astrophysics Data System (ADS)

    Liang, Xiaojing; Wen, Guiqing; Liu, Qingye; Liang, Aihui; Jiang, Zhiliang

    2016-09-01

    In acidic solutions, Bi(III) was reduced by NaBH4 to form BiH3 gas. Using I3- graphene oxide (GO) as absorption solution, the BiH3 gas reacted with I3- to form I- that resulted in the I3- concentration decreasing. In the absence of BiH3, the I3- concentration was high, and as receptors it was closed to the surfaces of GO which was as donors. Then the surface plasmon resonance Rayleigh scattering (RRS) energy of GO transfers to I3- heavily, and results in the RRS quenching severely. With the increase of the Bi(III) concentration, the receptors and the RRS energy transfer (RRS-ET) decreased, so the RRS intensity enhanced linearly at 370 nm. The RRS intensity was linear to the Bi(III) concentration in 0.05-5.5 μmol/L, with a detection limit of 4 ng/mL Bi. A new RRS-ET spectral method was developed for the determination of trace Bi(III). Using I3- as the absorption solution, silver nanorod (AgNR) as sol substrate and Vitoria blue B (VBB) as molecular probe, a SERS method was developed for detection of Bi.

  7. Resonance Rayleigh scattering method for highly sensitive detection of chitosan using aniline blue as probe.

    PubMed

    Zhang, Weiai; Ma, Caijuan; Su, Zhengquan; Bai, Yan

    2016-11-01

    This paper describes a highly sensitive and accurate approach using aniline blue (AB) (water soluble) as a probe to determine chitosan (CTS) through Resonance Rayleigh scattering (RRS). Under optimum experimental conditions, the intensities of RRS were linearly proportional to the concentration of CTS in the range from 0.01 to 3.5μg/mL, and the limit of detection (LOD) was 6.94ng/mL. Therefore, a new and highly sensitive method based on RRS for the determination of CTS has been developed. Furthermore, the effect of molecular weight of CTS and the effect of the degree of deacetylation of CTS on the accurate quantification of CTS was studied. The experimental data was analyzed by linear regression analysis, which indicated that the molecular weight and the degree of deacetylation of CTS had no statistical significance and this method could be used to determine CTS accurately. Meanwhile, this assay was applied for CTS determination in health products with satisfactory results. PMID:27294549

  8. Resonance Rayleigh scattering method for the determination of cationic surfactants with chromium(VI)-iodide system.

    PubMed

    Liu, Shaopu; Shi, Yan; Liu, Zhongfang; Luo, Hongqun; Kong, Ling

    2006-05-01

    A method for detecting and identifying cationic surfactant in some chemical samples for daily use that include Head & Shoulder Ampoule and Slek Shower Lotion has been developed. In an acid medium, chromium(VI) oxidizes I(-) to produce I(2), I(2) binds excess of I(-) to form I(3)(-), and I(3)(-) can further react with a cationic surfactant (CS) (such as cetyldimethyl benzylammonium chloride (CDBAC), Zephiramine (Zeph), cetylpyridinium bromide (CPB), tetradecyl pyridinium bromide (TPB) and cetyltrimethylammonium bromide (CTAB)) to form ion-association complexes [CS][I(3)]. This results in a significant enhancement of resonance Rayleigh scattering (RRS) and appearance of new RRS spectra. The RRS spectral characteristics of the ion-association complexes, the influencing factors and the optimum conditions of the reactions have been investigated. The intensities of RRS are directly proportional to the concentration of CS. CS in samples are collected using a treated anion exchange column and subsequently complexed by I(3)(-); then the RRS intensities of CS complex are determined at 495 nm. The reactions have high sensitivities, and their detection limits are 7.05 - 9.62 ng/mL for different CS. The effects of foreign substances are investigated and the results show that the method has good selectivity. PMID:16770060

  9. Measurement of the thermal diffusivity of liquids by the forced Rayleigh scattering method: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Nagasaka, Y.; Hatakeyama, T.; Okuda, M.; Nagashima, A.

    1988-07-01

    This article is devoted to the theory and experiment of the forced Rayleigh scattering method for measurement of thermal diffusivity of liquids which can be employed in the form of an instrument operated optically in a contact-free manner. The theoretical considerations included are: (1) effect of cell wall, (2) effect of dye, (3) effect of Gaussian beam intensity distribution, (4) effect of heating duration time, and (5) effect of coupled dye and wall for a heavily absorbing sample. The errors caused by inadequate setting of optical conditions are also analyzed: (1) effects of grating thickness and (2) effects of initial temperature amplitude. Experimental verifications of the theory have been carried out through the measurements on toluene and water as standard reference substances. As a result of these experiments and theory, the criteria for optimum measuring conditions became available. To demonstrate the applicability of the present theory and the apparatus, the thermal diffusivities of toluene and methanol have been measured near room temperature under atmospheric pressure. The accuracy of the present measurement is estimated to be ±3%.

  10. Coupling of a single diamond nanocrystal to a whispering-gallery microcavity: Photon transport benefitting from Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Liu, Yong-Chun; Xiao, Yun-Feng; Li, Bei-Bei; Jiang, Xue-Feng; Li, Yan; Gong, Qihuang

    2011-07-01

    We study the Rayleigh scattering induced by a diamond nanocrystal in a whispering-gallery-microcavity-waveguide coupling system and find that it plays a significant role in the photon transportation. On the one hand, this study provides insight into future solid-state cavity quantum electrodynamics aimed at understanding strong-coupling physics. On the other hand, benefitting from this Rayleigh scattering, effects such as dipole-induced transparency and strong photon antibunching can occur simultaneously. As a potential application, this system can function as a high-efficiency photon turnstile. In contrast to B. Dayan [ScienceSCIEAS0036-807510.1126/science.1152261 319, 1062 (2008)], the photon turnstiles proposed here are almost immune to the nanocrystal’s azimuthal position.

  11. Coupling of a single diamond nanocrystal to a whispering-gallery microcavity: Photon transport benefitting from Rayleigh scattering

    SciTech Connect

    Liu Yongchun; Xiao Yunfeng; Li Beibei; Jiang Xuefeng; Li Yan; Gong Qihuang

    2011-07-15

    We study the Rayleigh scattering induced by a diamond nanocrystal in a whispering-gallery-microcavity-waveguide coupling system and find that it plays a significant role in the photon transportation. On the one hand, this study provides insight into future solid-state cavity quantum electrodynamics aimed at understanding strong-coupling physics. On the other hand, benefitting from this Rayleigh scattering, effects such as dipole-induced transparency and strong photon antibunching can occur simultaneously. As a potential application, this system can function as a high-efficiency photon turnstile. In contrast to B. Dayan et al. [Science 319, 1062 (2008)], the photon turnstiles proposed here are almost immune to the nanocrystal's azimuthal position.

  12. Semi-classical dynamics of superradiant Rayleigh scattering in a Bose-Einstein condensate

    NASA Astrophysics Data System (ADS)

    Müller, J. H.; Witthaut, D.; le Targat, R.; Arlt, J. J.; Polzik, E. S.; Hilliard, A. J.

    2016-10-01

    Due to its coherence properties and high optical depth, a Bose-Einstein condensate [BEC] provides an ideal setting to investigate collective atom-light interactions. Superradiant light scattering [SLS] in a BEC is a fascinating example of such an interaction. It is an analogous process to Dicke superradiance, in which an electronically inverted sample decays collectively, leading to the emission of one or more light pulses in a well-defined direction. Through time-resolved measurements of the superradiant light pulses emitted by an end-pumped BEC, we study the close connection of SLS with Dicke superradiance. A 1D model of the system yields good agreement with the experimental data and shows that the dynamics result from the structures that build up in the light and matter-wave fields along the BEC. This paves the way for exploiting the atom-photon correlations generated by the superradiance.

  13. Half space albedo problem for the nonconservative vector equation of transfer with a combination of Rayleigh and isotropic scattering

    NASA Astrophysics Data System (ADS)

    Şenyiğit, M.

    2016-09-01

    The half-space albedo problem has been solved for a combination of Rayleigh and isotropic scattering using HN method which is developed for the neutron transport studies. The numerical results are compared with exact values obtained using variational method and Chandrasekhar's equation for the {H}-matrix. The analytical solutions of HN method are easy to handle in comparison with the other methods. The numerical results are in good agreement with previous works in literature.

  14. High performance liquid chromatography coupled with resonance Rayleigh scattering for the detection of three fluoroquinolones and mechanism study.

    PubMed

    Zhou, Mingqiong; Peng, Jingdong; He, Rongxing; He, Yuting; Zhang, Jing; Li, Aiping

    2015-02-01

    A reliable and versatile high performance liquid chromatography coupled with resonance Rayleigh scattering method was established for the determination of three fluoroquinolones, including levofloxacin, norfloxacin and enrofloxacin in water sample and human urine sample. In pH 4.4-4.6 Britton-Robinson buffer medium, the fluoroquinolones separated by high performance liquid chromatography could react with erythrosine to form 1:1 ion-association complexes, which could make contributions to the great enhancement of RRS. The resonance Rayleigh scattering signal was recorded at λex=λem=330 nm. The resonance Rayleigh scattering spectral characteristics of the drugs and the experimental conditions such as pH, detection wavelength, erythrosine concentration, flow rate, the length of reaction tube were studied. Quantum chemistry calculation, Fourier transform infrared spectroscopy and absorption spectroscopy were used to discuss the reaction mechanism. The recoveries of samples added standard ranged from 97.53% to 102.00%, and the relative standard deviation was below 4.64%. The limit of detection (S/N=3) of 0.05-0.12 μg mL(-1) was reached, and the linear regression coefficients were all above 0.999. The proposed method was proved as a simple, low cost and high sensitivity method.

  15. Microscopic Imaging and Spectroscopy with Scattered Light

    PubMed Central

    Boustany, Nada N.; Boppart, Stephen A.; Backman, Vadim

    2012-01-01

    Optical contrast based on elastic scattering interactions between light and matter can be used to probe cellular structure and dynamics, and image tissue architecture. The quantitative nature and high sensitivity of light scattering signals to subtle alterations in tissue morphology, as well as the ability to visualize unstained tissue in vivo, has recently generated significant interest in optical scatter based biosensing and imaging. Here we review the fundamental methodologies used to acquire and interpret optical scatter data. We report on recent findings in this field and present current advances in optical scatter techniques and computational methods. Cellular and tissue data enabled by current advances in optical scatter spectroscopy and imaging stand to impact a variety of biomedical applications including clinical tissue diagnosis, in vivo imaging, drug discovery and basic cell biology. PMID:20617940

  16. A novel method for the determination of fast green in grape wine based on resonance Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Li, Qin; Tan, Xuanping; Zheng, Xiaobo; Tang, Weiwei; Yang, Jidong

    2015-11-01

    A novel resonance Rayleigh scattering method was developed for the determination of fast green (FCF) in grape wine. In pH 2.5 Britton Robinson (BR) buffer solution, the scattering signal of acridine orange (AO) was remarkably enhanced after adding trace amount of FCF and forming an ion-association complex, which not only resulted in the change of absorption spectrum, fluorescence spectra, but also led to a significant enhancement of resonance Rayleigh scattering (RRS), frequency doubling scattering (FDS), and second order scattering (SOS). The linear ranges and detection limits for RRS, SOS and FDS were 2-45 × 10-6 mol L-1, 2-24 × 10-6 mol L-1, 2-20 × 10-6 mol L-1, and 8.0 × 10-8 mol L-1, 4.7 × 10-7 mol L-3, 1.0 × 10-7 mol L-3, respectively. In this work, the optimum conditions, the influencing factors and the effects of coexisting substances on the reaction were investigated. The method can be applied to the determination of FCF in grape wine and the results were satisfactory.

  17. Birefringence and scattering of light in colloidal solutions of magnetite in kerosene

    NASA Astrophysics Data System (ADS)

    Erin, K. V.

    2016-02-01

    The birefringence and dynamic and static scattering of light in colloidal solutions of magnetite nanoparticles in kerosene with different concentrations of the solid phase have been investigated. It is shown that these solutions contain both individual colloidal particles about 12 nm in diameter and their aggregates up to 100‒600 nm in diameter. The largest aggregates are formed in solutions with the lowest concentration (on the order of 0.001 vol % or lower). The presence of relatively large aggregates makes it possible to observe specific features of optical anisotropy relaxation in these solutions, which are related to the non-Rayleigh character of light scattering from magnetite-particle aggregates.

  18. Microscope spectrometer for light scattering investigations

    SciTech Connect

    Barbara, Aude; Lopez-Rios, Tomas; Dumont, Sylvain; Gay, Frederic; Quemerais, Pascal

    2010-08-01

    We describe a setup including a microscope to study volumes of a few {mu}m{sup 3} by static and dynamic light scattering (DLS) in a backscattering configuration. Light scattered by individual objects of micrometric size can be analyzed in the 400-800 nm spectral range. This setup can also be employed to study both diluted and concentrated colloidal solutions by DLS measurements. For diluted solutions we found evidence of the fluctuations of the number of particles in a confocal volume. We discuss their contribution to the autocorrelation function of the scattered intensity measured as a function of time.

  19. Scalar gradient trajectory measurements using high-frequency cinematographic planar Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Gampert, Markus; Narayanaswamy, Venkat; Peters, Norbert

    2013-12-01

    In this work, we perform an experimental investigation into statistics based on scalar gradient trajectories in a turbulent jet flow, which have been suggested as an alternative means to analyze turbulent flow fields by Wang and Peters (J Fluid Mech 554:457-475, 2006, 608:113-138, 2008). Although there are several numerical simulations and theoretical works that investigate the statistics along gradient trajectories, only few experiments in this area have been reported. To this end, high-frequency cinematographic planar Rayleigh scattering imaging is performed at different axial locations of a turbulent propane jet issuing into a CO2 coflow at nozzle-based Reynolds numbers Re 0 = 3,000-8,600. Taylor's hypothesis is invoked to obtain a three-dimensional reconstruction of the scalar field in which then the corresponding scalar gradient trajectories can be computed. These are then used to examine the local structure of the mixture fraction with a focus on the scalar turbulent/non-turbulent interface. The latter is a layer that is located between the fully turbulent part of the jet and the outer flow. Using scalar gradient trajectories, we partition the turbulent scalar field into these three regions according to an approach developed by Mellado et al. (J Fluid Mech 626:333-365, 2009). Based on the latter, we investigate the probability to find the respective regions as a function of the radial distance to the centerline, which turns out to reveal the meandering nature of the scalar T/NT interface layer as well as its impact on the local structure of the turbulent scalar field.

  20. SEARCH FOR RAYLEIGH SCATTERING IN THE ATMOSPHERE OF GJ1214b

    SciTech Connect

    De Mooij, E. J. W.; Jayawardhana, R.; Brogi, M.; Snellen, I. A. G.; Hoekstra, H.; Otten, G. P. P. L.; Bekkers, D. H.; Haffert, S. Y.; Van Houdt, J. J.; De Kok, R. J.; Croll, B.

    2013-07-10

    We investigate the atmosphere of GJ1214b, a transiting super-Earth planet with a low mean density, by measuring its transit depth as a function of wavelength in the blue optical portion of the spectrum. It is thought that this planet is either a mini-Neptune, consisting of a rocky core with a thick, hydrogen-rich atmosphere, or a planet with a composition dominated by water. Most observations favor a water-dominated atmosphere with a small scale-height, however, some observations indicate that GJ1214b could have an extended atmosphere with a cloud layer muting the molecular features. In an atmosphere with a large scale-height, Rayleigh scattering at blue wavelengths is likely to cause a measurable increase in the apparent size of the planet toward the blue. We observed the transit of GJ1214b in the B band with the FOcal Reducing Spectrograph at the Very Large Telescope and in the g band with both ACAM on the William Herschel Telescope (WHT) and the Wide Field Camera at the Isaac Newton Telescope (INT). We find a planet-to-star radius ratio in the B band of 0.1162 {+-} 0.0017, and in the g band 0.1180 {+-} 0.0009 and 0.1174 {+-} 0.0017 for the WHT and INT observations, respectively. These optical data do not show significant deviations from previous measurements at longer wavelengths. In fact, a flat transmission spectrum across all wavelengths best describes the combined observations. When atmospheric models are considered, a small scale-height water-dominated model fits the data best.

  1. Pushing the upper limit of Rayleigh-scatter Temperatures Retrievals into the Lower Thermosphere Using an Inversion Approach

    NASA Astrophysics Data System (ADS)

    Bandoro, J.; Sica, R. J.; Argall, S.

    2012-12-01

    An important aspect of solar terrestrial relations is the coupling between the lower and upper atmosphere-ionosphere system. The coupling is evident in the general circulation of the atmosphere, where waves generate in the lower atmosphere play an important role in the dynamics of the upper atmosphere, which feeds back on the lower atmosphere's circulation. To address coupling problems requires measurements over the broadest range of heights possible. A recently developed retrieval method for temperature profiles from Rayleigh-scatter lidar measurements using an inversion approach allows the upward extension of the altitude range of temperature by 10 to 15 km over the conventional method, thus producing the equivalent of increasing the systems power-aperture product by 4 times [1]. The method requires no changes to the lidar's hardware and thus, can be applied to the body of existing measurements. In addition, since the uncertainties of the retrieved temperature profile are found by a Monte Carlo error analysis, it is possible to isolate systematic and random uncertainties to model the effect of each one on the final uncertainty product for the temperature profile. This unambiguous separation of uncertainties was not previously possible as only the propagation of the statistical uncertainties are typically reported. For the Purple Crow Lidar, corrections for saturation (e.g. non-linearity) in the photocount returns, ozone extinction and background removal all contribute to the overall systematic uncertainty. Results of individually varying each systematic correction and the effect on the final temperature uncertainty through Monte Carlo realizations are presented to determine the importance for each one. For example, it was found that treatment of the background correction as a systematic versus statistical uncertainty gave results in agreement with each other. This new method is then applied to measurements obtained by the Purple Crow lidar' Rayleigh-scatter

  2. Effect of molecular anisotropy on the intensity and degree of polarization of light scattered from model atmospheres

    NASA Technical Reports Server (NTRS)

    Bahethi, O. P.; Fraser, R. S.

    1975-01-01

    Computations of the intensity, flux, degree of polarization, and the positions of neutral points are presented for models of the terrestrial gaseous and hazy atmospheres by incorporating the molecular anisotropy due to air in the Rayleigh scattering optical thickness and phase matrix. Molecular anisotropy causes significant changes in the intensity, flux and the degree of polarization of the scattered light. The positions of neutral points do not change significantly. When the Rayleigh scattering optical thickness is kept constant and the molecular anisotropy factor is included only in the Rayleigh phase matrix, the flux does not change and the intensity and positions of neutron points change by a small amount. The changes in the degree of polarization are still significant.

  3. Hadronic light-by-light scattering in muonium hyperfine splitting

    SciTech Connect

    Karshenboim, S. G.; Shelyuto, V. A.; Vainshtein, A. I.

    2008-09-15

    We consider an impact of hadronic light-by-light scattering on the muonium hyperfine structure. A shift of the hyperfine interval {delta}{nu}(Mu){sub HLBL} is calculated with the light-by-light scattering approximated by the exchange of pseudoscalar and pseudovector mesons. Constraints from the operator product expansion in QCD are used to fix parameters of the model similar to the one used earlier for the hadronic light-by-light scattering in calculations of the muon anomalous magnetic moment. The pseudovector exchange is dominant in the resulting shift, {delta}{nu}(Mu){sub HLBL}=-0.0065(10) Hz. Although the effect is tiny it is useful in understanding the level of hadronic uncertainties.

  4. Fiber optic probe for light scattering measurements

    DOEpatents

    Nave, Stanley E.; Livingston, Ronald R.; Prather, William S.

    1995-01-01

    A fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman-scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

  5. Fiber optic probe for light scattering measurements

    DOEpatents

    Nave, S.E.; Livingston, R.R.; Prather, W.S.

    1993-01-01

    This invention is comprised of a fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman- scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

  6. The Whiteness of Things and Light Scattering

    ERIC Educational Resources Information Center

    Gratton, L. M.; Lopez-Arias, T.; Calza, G.; Oss, S.

    2009-01-01

    We discuss some simple experiments dealing with intriguing properties of light and its interaction with matter. In particular, we show how to emphasize that light reflection, refraction and scattering can provide a proper, physical description of human perception of the "colour" white. These experiments can be used in the classroom with an enquiry…

  7. Polarization of light scattered by clover

    NASA Technical Reports Server (NTRS)

    Woessner, Paul; Hapke, Bruce

    1987-01-01

    This study was undertaken in order to better understand the factors that govern the polarization of light scattered from vegetation and soils. This phenomenon is not well understood but is potentially of interest for remote sensing of the earth. The intensity and polarization of light scattered by clover in vivo and soil were measured at a number of different angles of incidence and reflectance. Both individual leaves and natural patches of vegetation were measured. The Umov effect, or inverse relation between polarization and reflectance noted by many earlier workers, was observed here and is shown to be a very general property of diffusely scattering surfaces. The light transmitted through the leaves was found to be negatively polarized. The polarization of light scattered from aggregations of leaves is affected by this negatively polarized, transmitted light. The light scattered from the upper leaf surfaces was found to be positively polarized in a manner which could be accounted for quantitatively by specular Fresnel reflection from small, randomly oriented facets on the surfaces of the leaves.

  8. Confocal detection of Rayleigh scattering for residual stress measurement in chemically tempered glass

    SciTech Connect

    Hödemann, S. Möls, P.; Kiisk, V.; Saar, R.; Kikas, J.; Murata, T.

    2015-12-28

    A new optical method is presented for evaluation of the stress profile in chemically tempered (chemically strengthened) glass based on confocal detection of scattered laser beam. Theoretically, a lateral resolution of 0.2 μm and a depth resolution of 0.6 μm could be achieved by using a confocal microscope with high-NA immersion objective. The stress profile in the 250 μm thick surface layer of chemically tempered lithium aluminosilicate glass was measured with a high spatial resolution to illustrate the capability of the method. The confocal method is validated using transmission photoelastic and Na{sup +} ion concentration profile measurement. Compositional influence on the stress-optic coefficient is calculated and discussed. Our method opens up new possibilities for three-dimensional scattered light tomography of mechanical imaging in birefringent materials.

  9. Confocal detection of Rayleigh scattering for residual stress measurement in chemically tempered glass

    NASA Astrophysics Data System (ADS)

    Hödemann, S.; Möls, P.; Kiisk, V.; Murata, T.; Saar, R.; Kikas, J.

    2015-12-01

    A new optical method is presented for evaluation of the stress profile in chemically tempered (chemically strengthened) glass based on confocal detection of scattered laser beam. Theoretically, a lateral resolution of 0.2 μm and a depth resolution of 0.6 μm could be achieved by using a confocal microscope with high-NA immersion objective. The stress profile in the 250 μm thick surface layer of chemically tempered lithium aluminosilicate glass was measured with a high spatial resolution to illustrate the capability of the method. The confocal method is validated using transmission photoelastic and Na+ ion concentration profile measurement. Compositional influence on the stress-optic coefficient is calculated and discussed. Our method opens up new possibilities for three-dimensional scattered light tomography of mechanical imaging in birefringent materials.

  10. Circularly symmetric light scattering from nanoplasmonic spirals.

    PubMed

    Trevino, Jacob; Cao, Hui; Dal Negro, Luca

    2011-05-11

    In this paper, we combine experimental dark-field imaging, scattering, and fluorescence spectroscopy with rigorous electrodynamics calculations in order to investigate light scattering from planar arrays of Au nanoparticles arranged in aperiodic spirals with diffuse, circularly symmetric Fourier space. In particular, by studying the three main types of Vogel's spirals fabricated by electron-beam lithography on quartz substrates, we demonstrate polarization-insensitive planar light diffraction in the visible spectral range. Moreover, by combining dark-field imaging with analytical multiparticle calculations in the framework of the generalized Mie theory, we show that plasmonic spirals support distinctive structural resonances with circular symmetry carrying orbital angular momentum. The engineering of light scattering phenomena in deterministic structures with circular Fourier space provides a novel strategy for the realization of optical devices that fully leverage on enhanced, polarization-insensitive light-matter coupling over planar surfaces, such as thin-film plasmonic solar cells, plasmonic polarization devices, and optical biosensors. PMID:21466155

  11. Light scattering study of rheumatoid arthritis

    SciTech Connect

    Beuthan, J; Netz, U; Minet, O; Mueller, G; Scheel, A; Henniger, J

    2002-11-30

    The distribution of light scattered by finger joints is studied in the near-IR region. It is shown that variations in the optical parameters of the tissue (scattering coefficient {mu}{sub s}, absorption coefficient {mu}{sub a}, and anisotropy factor g) depend on the presence of the rheumatoid arthritis (RA). At the first stage, the distribution of scattered light was measured in diaphanoscopic experiments. The convolution of a Gaussian error function with the scattering phase function proved to be a good approximation of the data obtained. Then, a new method was developed for the reconstruction of distribution of optical parameters in the finger cross section. Model tests of the quality of this reconstruction method show good results. (laser biology and medicine)

  12. Modeling stray light from rough surfaces and subsurface scatter

    NASA Astrophysics Data System (ADS)

    Harvey, James E.; Goshy, John J.; Pfisterer, Richard N.

    2014-09-01

    Over the years we have developed an adequate theory and understanding of surface scatter from smooth optical surfaces (Rayleigh-Rice), moderately rough surfaces with paraxial incident and scattered angles (Beckmann- Kirchhoff) and even for moderately rough surfaces with arbitrary incident and scattered angles where a linear systems formulation requiring a two-parameter family of surface transfer functions is required to characterize the surface scatter process (generalized Harvey-Shack). However, there is always some new material or surface manufacturing process that provides non-intuitive scatter behavior. The linear systems formulation of surface scatter is potentially useful even for these situations. In this paper we will present empirical models of several classes of rough surfaces or materials (subsurface scatter) that allow us to accurately model the scattering behavior at any incident angle from limited measured scatter data. In particular, scattered radiance appears to continue being the natural quantity that exhibits simple, elegant behavior only in direction cosine space.

  13. [DNAzyme cracking-nanogold resonance Rayleigh scattering spectral method for the determination of trace Cu2+].

    PubMed

    Wang, Sheng-Mian; Wu, Meng; Liang, Ai-Hui; Jiang, Zhi-Liang

    2013-01-01

    In the condition of pH 7.0 HEPES buffer solution and 0.19 mol x L(-1) NaCl, the substrate strand DNA (SS) and the enzyme strand DNA (ES) hybridized into a double-stranded DNA (dsDNA) at 80 degrees C. The substrate chain of dsDNA could be cracked by Cu2+, and the released single-stranded DNA (ssDNA) were adsorbed on the nanogold(NG) surface to produce a stable NGssDNA conjugate. The unprotected NG was aggregated to form NG aggregation (NGA) that exhibited a resonance Rayleigh scattering (RRS) peak at 627 nm. When the Cu2+ was added, the NGssDNA increased, and the NGA decreased that caused the RRS intensity decreasing at 627 nm, and the solution color changed from blue to red. The decreased RS intensity deltaI was linear with the Cu2+ was added, the NGssDNA increased, and the NGA decreased that caused the RRS intensity decreasing at 627 nm, the solution color changed from blue to red. The decreased RS intensity deltaI was linear to the Cu2+ concentration in the range of 15-1 250 nmol x L(-1), with a regression equation of deltaI = 0.17c-2.3, coefficient of 0.989 5 and a detection limit of 8 nmol x L(-1) Cu2+. In addition, the influence of foreign substances on the determination of 0.75 micromol x L(-1) Cu2+ was considered. The results show that 3 micro mol x L(-1) Ca2+, Pb2+ and Hg2+, 2 micromol x L(-1) Fe2+, 1 micromol x L(-1) Sn2+, 4 micromol x L(-1) Al3+, 12 micromol x L(-1) Mn2+, 4 micromol x L(-1) Co2+ and Ni2+ did not interfered with the determination. This indicates that this method has good selectivity. This new, rapid, sensitive, selective RRS method was applied to the determination of Cu2+ in water, with satisfactory results.

  14. Laser light scattering instrument advanced technology development

    NASA Technical Reports Server (NTRS)

    Wallace, J. F.

    1993-01-01

    The objective of this advanced technology development (ATD) project has been to provide sturdy, miniaturized laser light scattering (LLS) instrumentation for use in microgravity experiments. To do this, we assessed user requirements, explored the capabilities of existing and prospective laser light scattering hardware, and both coordinated and participated in the hardware and software advances needed for a flight hardware instrument. We have successfully breadboarded and evaluated an engineering version of a single-angle glove-box instrument which uses solid state detectors and lasers, along with fiber optics, for beam delivery and detection. Additionally, we have provided the specifications and written verification procedures necessary for procuring a miniature multi-angle LLS instrument which will be used by the flight hardware project which resulted from this work and from this project's interaction with the laser light scattering community.

  15. Angular resolved light scattering for discriminating among marine picoplankton: modeling and experimental measurements

    NASA Astrophysics Data System (ADS)

    Shao, Bing; Jaffe, Jules S.; Chachisvilis, Mirianas; Esener, Sadik C.

    2006-12-01

    In order to assess the capability to optically identify small marine microbes, both simulations and experiments of angular resolved light scattering (ARLS) were performed. After calibration with 30-nm vesicles characterized by a nearly constant scattering distribution for vertically polarized light (azimuthal angle=90°), ARLS from suspensions of three types of marine picoplankton (two prokaryotes and one eukaryote) in seawater was measured with a scattering device that consisted of an elliptical mirror, a rotating aperture, and a PMT. Scattered light was recorded with adequate signal-to-noise in the 40-140°. Simulations modeled the cells as prolate spheroids with independently measured dimensions. For the prokaryotes, approximated as homogeneous spheroids, simulations were performed using the RM (Rayleigh-Mie) - I method, a hybrid of the Rayleigh-Debye approximation and the generalized Lorentz-Mie theory. For the picoeukaryote, an extended RM - I method was developed for a coated spheroid with different shell thickness distributions. The picoeukaryote was then modeled as a coated sphere with a spherical core. Good overall agreements were obtained between simulations and experiments. The distinctive scattering patterns of the different species hold promise for an identification system based on ARLS.

  16. Study on the interaction between fluoroquinolones and erythrosine by absorption, fluorescence and resonance Rayleigh scattering spectra and their application

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Liu, Zhongfang; Liu, Jiangtao; Liu, Shaopu; Shen, Wei

    2008-03-01

    In pH 4.4-4.5 Britton-Robinson (BR) buffer solution, fluoroquinolone antibiotics (FLQs) including ciprofloxacin (CIP), norfloxacin (NOR), levofloxacin (LEV) and lomefloxacin (LOM) could react with erythrosine (Ery) to form 1:1 ion-association complexes, which not only resulted in the changes of the absorption spectra and the quenching of fluorescence, but also resulted in the great enhancement of resonance Rayleigh scattering (RRS). These offered some indications of the determination of fluoroquinolone antibiotics by spectrophotometric, fluorescence and resonance Rayleigh scattering methods. The detection limits for fluoroquinolone antibiotics were in the range of 0.097-0.265 μg/mL for absorption methods, 0.022-0.100 μg/mL for fluorophotometry and 0.014-0.027 μg/mL for RRS method, respectively. Among them, the RRS method had the highest sensitivity. In this work, the spectral characteristics of the absorption, fluorescence and RRS, the optimum conditions of the reactions and the properties of the analytical chemistry were investigated. The methods have been successfully applied to determination of some fluoroquinolone antibiotics in human urine samples and tablets. Taking CIP-Ery system as an example, the charge distribution, the enthalpy of formation and the mean polarizability were calculated by density function theory (DFT) method. In addition, the reasons for the enhancement of scattering spectra were discussed.

  17. Light-induced scattering in photorefractive crystals

    NASA Astrophysics Data System (ADS)

    Rupp, R. A.; Drees, F. W.

    1986-04-01

    Light-induced scattering features in LiNbO3- and BaTiO3-crytals are compared with theories on holographic writing in photorefractive crystals. It is shown that they describe the experimental facts concerning the expected main scattering directions for a given incident polarization, the time development, the thickness and the wavelength dependence. Time records of the transmission offer a useful alternative for the determination of the photoconductivity. Furthermore, a new method for birefringence measurements is established. The high accuracy of this method is based on the automatic fulfillment of a phase matching condition by the anisotropically scattered radiation.

  18. Study of the pair correlations between p-nitroaniline molecules in solution by depolarized hyper-Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Chan, Y. C.; Wong, K. Y.

    2012-05-01

    The concentration dependence of the hyper-Rayleigh scattering depolarization ratios of p-nitroaniline in solution was obtained and the results were compared with theory. It was found that the experimental data can be theoretically accounted for by using a pair distribution function that includes only direct correlation, with the molecules interact through a dipolar hard-sphere potential. The results show that short-range dipole-dipole interactions are responsible for the correlation between pairs of p-nitroaniline molecules in solution.

  19. Improvements in filtered Rayleigh scattering measurements using Fabry-Perot etalons for spectral filtering of pulsed, 532-nm Nd:YAG output

    NASA Astrophysics Data System (ADS)

    Sutton, Jeffrey A.; Patton, Randy A.

    2014-09-01

    In this manuscript, we investigate a new methodology for increasing the spectral purity of the second-harmonic output of an injection-seeded, frequency-doubled, Q-switched Nd:YAG laser operating near 532 nm. Specifically, tunable Fabry-Perot etalons (FPEs) are used as ultra-narrowband spectral filters, transmitting the desired single-mode output, while filtering out a significant portion of the broadband pedestal characteristic of injection-seeded lasers. A specific emphasis is placed on the design and optimization of the FPEs in the context of filtered Rayleigh scattering (FRS) measurements and how their utilization results in substantial increases in spectral purity, realizable attenuation of unwanted scattering, and applications in environments with high particulate levels. Experimental results show an increase in laser spectral purity of more than one order-of-magnitude (from 0.99997 to 0.999998) when using FPE filters, which led to a two-order-of-magnitude increase in achievable attenuation of laser light passing through a molecular iodine filter. The utility of the FPE-based spectral filtering of the pulsed Nd:YAG output for 2D FRS imaging was demonstrated in turbulent, isothermal gas-phase jets, seeded with varying levels of non-evaporating droplets with particle volume fractions ( F Vp) ranging from ~5 to >60 parts-per-million (ppm). After implementation of an optimized air-spaced FPE in the 532-nm output, no particle scattering was observed (based on visual and statistical analysis), even for the highest seed case ( F Vp ~ 60 ppm), and the gas-phase Rayleigh-Brillouin signals were collected without interference from the flowfield particulate. The current results suggest that the implementation of properly specified FPEs allows FRS to be applied in environments with high flowfield particulate levels; levels are well beyond what have been suitable for previous FRS measurements.

  20. Scattered light in Galactic H II Regions

    NASA Astrophysics Data System (ADS)

    Robledo-Rella, V.

    2002-02-01

    We find that dust-scattered light is the dominant contributor (50-70%) to the continuum in the pure nebular spectra (bright stars excluded) of NGC 3372 (Carina), M8 and M20. On the other hand, the stellar spectra contributes only about 50% of the continuum when the stars are included. This high contribution of scattered light should be taken into account when deriving the age and stellar content from observed Equivalent Widths ( W[H scriptstyle beta ]) in spatially resolved GEHRs and H II galaxies.

  1. A dual-wavelength overlapping resonance Rayleigh scattering method for the determination of chondroitin sulfate with nile blue sulfate

    NASA Astrophysics Data System (ADS)

    Cui, Zhiping; Hu, Xiaoli; Liu, Shaopu; Liu, Zhongfang

    2011-12-01

    A dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS) method was developed to detect chondroitin sulfate (CS) with nile blue sulfate (NBS). At pH 3.0-4.0 Britton-Robinson (BR) buffer medium, CS interacted with NBS to form an ion-association complex. As a result, the new spectra of resonance Rayleigh scattering (RRS), second order scattering (SOS) and frequence doubling scattering (FDS) appeared and their intensities were enhanced greatly. Their maximum wavelengths were located at 303 nm (RRS), 362 nm (RRS), 588 nm (SOS) and 350 nm (FDS), respectively. The scattering intensities of the three methods were proportional to the concentration of CS in certain ranges. The methods had high sensitivity and the detection limits were between 1.5 and 7.1 ng mL -1. The DWO-RRS method had the highest sensitivity with the detection limit being 1.5 ng mL -1. The characteristics of the spectra and optimal reaction conditions of RRS method were investigated. The effects of coexistent substances on the determination of CS were evaluated. Owing to the high sensitivity, RRS method had been applied to the determination of CS in eye drops with satisfactory results. The recovery range was between 99.4% and 104.6% and the relative standard deviation (RSD) was between 0.4% and 0.8%. In addition, the reasons for RRS enhancement were discussed and the shape of ion-association complex was characterized by atomic force microscopy (AFM).

  2. Radiance and polarization of multiple scattered light from haze and clouds.

    PubMed

    Kattawar, G W; Plass, G N

    1968-08-01

    The radiance and polarization of multiple scattered light is calculated from the Stokes' vectors by a Monte Carlo method. The exact scattering matrix for a typical haze and for a cloud whose spherical drops have an average radius of 12 mu is calculated from the Mie theory. The Stokes' vector is transformed in a collision by this scattering matrix and the rotation matrix. The two angles that define the photon direction after scattering are chosen by a random process that correctly simulates the actual distribution functions for both angles. The Monte Carlo results for Rayleigh scattering compare favorably with well known tabulated results. Curves are given of the reflected and transmitted radiances and polarizations for both the haze and cloud models and for several solar angles, optical thicknesses, and surface albedos. The dependence on these various parameters is discussed.

  3. NONLINEAR OPTICS PHENOMENA: Nonlinear light scattering in a carbon nanotube suspension

    NASA Astrophysics Data System (ADS)

    Mikheev, Gen M.; Mogileva, T. N.; Okotrub, Aleksandr V.; Bulatov, D. L.; Vanyukov, V. V.

    2010-01-01

    Nonlinear scattering of 1064-nm laser light in an aqueous suspension of purified carbon nanotubes has been studied in relation to their optical power limiting behaviour using z-scan measurements to simultaneously determine the energy and shape of the transmitted and 90° circ-scattered pulses. The results indicate that the reduction in transmitted laser pulse energy with increasing incident power density is mainly due to the associated increase in scattered pulse energy. The shape, duration and time shift of the transmitted and 90° circ-scattered pulses are intricate functions of incident power density. The data are interpreted in terms of thermally induced nonlinear and Rayleigh scattering processes at high and low incident power densities, respectively.

  4. Light scattering by a reentrant fractal surface.

    PubMed

    Mendoza-Suárez, A; Méndez, E R

    1997-05-20

    Recently, rigorous numerical techniques for treating light scattering problems with one-dimensional rough surfaces have been developed. In their usual formulation, these techniques are based on the solution of two coupled integral equations and are applicable only to surfaces whose profiles can be described by single-valued functions of a coordinate in the mean plane of the surface. In this paper we extend the applicability of the integral equation method to surfaces with multivalued profiles. A procedure for finding a parametric description of a given profile is described, and the scattering equations are established within the framework of this formalism. We then present some results of light scattering from a sequence of one-dimensional flat surfaces with defects in the form of triadic Koch curves. Beyond a certain order of the prefractal, the scattering patterns become stationary (within the numerical accuracy of the method). It can then be argued that the results obtained correspond to a surface with a fractal structure. These constitute, to our knowledge, the first rigorous calculations of light scattering from a reentrant fractal surface. PMID:18253371

  5. Light scattering by randomly oriented crystals

    NASA Astrophysics Data System (ADS)

    Muinonen, Karri; Lumme, Kari; Peltoniemi, Jouni; Irvine, William M.

    The scattering phase function and the degree of linear polarization for small crystals oriented randomly in space have been computed using the geometric ray tracing theory and assuming that the crystals are homogeneous and isotropic. Calculations have been carried out for the main crystal geometries. Detection of halos from crystals other than hexagonal water ice is briefly discussed. The crystal size and shape parameters have also been averaged over some simple distributions in order to examine general light scattering properties of sharp-edged particles. A scalar physical optics correction has been developed for the geometric optics phase functions. Results can be applied to light scattering from regoliths and planetary rings, and possibly also to atmospheric halos. Retroreflecting crystals in the regolith would cause an opposition spike, a phenomenon observed for many bright satellites.

  6. Light Scattering based detection of food pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current methods for detecting foodborne pathogens are mostly destructive (i.e., samples need to be pretreated), and require time, personnel, and laboratories for analyses. Optical methods including light scattering based techniques have gained a lot of attention recently due to its their rapid a...

  7. Noise induced in optical fibers by double Rayleigh scattering of a laser with a 1/fν frequency noise.

    PubMed

    Fleyer, Michael; Heerschap, Seth; Cranch, Geoffrey A; Horowitz, Moshe

    2016-03-15

    We study, theoretically and experimentally, intensity noise induced by double Rayleigh scattering in long optical fibers. The results of the theoretical model are compared to experimental results performed with a high-coherence-length laser with a frequency noise spectrum that is dominated by 1/fν noise. Excellent quantitative agreement between theoretical and experimental RF spectra were obtained for frequencies as low as 10 Hz and for fiber lengths between 4 and 45 km. Strong low-frequency intensity noise that is induced by 1/fν frequency noise of the laser may limit the performance of interferometric fiber optic sensors that require high-coherence-length lasers. The intensity noise due to double Rayleigh backscattering can be suppressed by reducing the coherence length of the laser. Therefore, the intensity noise has a complex and non-monotonic dependence on the 1/fν frequency noise amplitude of the laser. Stimulated Brillouin scattering will add a significant noise for input powers greater than about 7 mW for a 30 km length fiber.

  8. New technique for retrieval of atmospheric temperature profiles from Rayleigh-scatter lidar measurements using nonlinear inversion.

    PubMed

    Khanna, Jaya; Bandoro, Justin; Sica, R J; McElroy, C Thomas

    2012-11-20

    The conventional method of calculating atmospheric temperature profiles using Rayleigh-scattering lidar measurements has limitations that necessitate abandoning temperatures retrieved at the greatest heights, due to the assumption of a pressure value required to initialize the integration at the highest altitude. An inversion approach is used to develop an alternative way of retrieving nightly atmospheric temperature profiles from the lidar measurements. Measurements obtained by the Purple Crow lidar facility located near The University of Western Ontario are used to develop and test this new technique. Our results show temperatures can be reliably retrieved at all heights where measurements with adequate signal-to-noise ratio exist. A Monte Carlo technique was developed to provide accurate estimates of both the systematic and random uncertainties for the retrieved nightly average temperature profile. An advantage of this new method is the ability to seed the temperature integration from the lowest rather than the greatest height, where the variability of the pressure is smaller than in the mesosphere or lower thermosphere and may in practice be routinely measured by a radiosonde, rather than requiring a rocket or satellite-borne measurement. Thus, this new technique extends the altitude range of existing Rayleigh-scatter lidars 10-15 km, producing the equivalent of four times the power-aperture product.

  9. Applicability of the Rayleigh-Gans approximation for scattering by snowflakes at microwave frequencies in vertical incidence

    NASA Astrophysics Data System (ADS)

    Tyynelä, J.; Leinonen, J.; Westbrook, C. D.; Moisseev, D.; Nousiainen, T.

    2013-02-01

    Abstract The applicability of the <span class="hlt">Rayleigh</span>-Gans approximation (RGA) for <span class="hlt">scattering</span> by snowflakes is studied in the microwave region of the electromagnetic spectrum. Both the shapes of the single ice crystals, or monomers, and their amounts in the modeled snowflakes are varied. For reference, the discrete-dipole approximation (DDA) is used to produce numerically accurate solutions to the single-<span class="hlt">scattering</span> properties, such as the backscattering and extinction cross-sections, single-<span class="hlt">scattering</span> albedo, and the asymmetry parameter. We find that the single-<span class="hlt">scattering</span> albedo is the most accurate with only about 10% relative bias at maximum. The asymmetry parameter has about 0.12 absolute bias at maximum. The backscattering and extinction cross-sections show about - 65% relative biases at maximum, corresponding to about - 4.6 dB difference. Overall, the RGA agrees well with the DDA computations for all the cases studied and is more accurate for the integrated quantities, such as the single-<span class="hlt">scattering</span> albedo and the asymmetry parameter than the cross-sections for the same snowflakes. The accuracy of the RGA seems to improve, when the number of monomers is increased in an aggregate, and decrease, when the frequency increases. It is also more accurate for less dense monomer shapes, such as stellar dendrites. The DDA and RGA results are well correlated; the sample correlation coefficients of those are close to unity throughout the study. Therefore, the accuracy of the RGA could be improved by applying appropriate correction factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013hcdo.book..565A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013hcdo.book..565A"><span id="translatedtitle">Quasi-Elastic <span class="hlt">Light</span> <span class="hlt">Scattering</span> in Ophthalmology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ansari, Rafat R.</p> <p></p> <p>The eye is not just a "window to the soul"; it can also be a "window to the human body." The eye is built like a camera. <span class="hlt">Light</span> which travels from the cornea to the retina traverses through tissues that are representative of nearly every tissue type and fluid type in the human body. Therefore, it is possible to diagnose ocular and systemic diseases through the eye. Quasi-elastic <span class="hlt">light</span> <span class="hlt">scattering</span> (QELS) also known as dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS) is a laboratory technique routinely used in the characterization of macromolecular dispersions. QELS instrumentation has now become more compact, sensitive, flexible, and easy to use. These developments have made QELS/DLS an important tool in ophthalmic research where disease can be detected early and noninvasively before the clinical symptoms appear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NIMPB.368..129P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NIMPB.368..129P"><span id="translatedtitle">Refinement of the Compton-<span class="hlt">Rayleigh</span> <span class="hlt">scatter</span> ratio method for use on the Mars Science Laboratory alpha particle X-ray spectrometer: II - Extraction of invisible element content</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perrett, Glynis M.; Campbell, John L.; Gellert, Ralf; King, Penelope L.; Nield, Emily; O'Meara, Joanne M.; Pradler, Irina</p> <p>2016-02-01</p> <p>The intensity ratio C/R between Compton and <span class="hlt">Rayleigh</span> <span class="hlt">scatter</span> peaks of the exciting Pu L X-rays in the alpha particle X-ray spectrometer (APXS) is strongly affected by the presence of very <span class="hlt">light</span> elements such as oxygen which cannot be detected directly by the APXS. C/R values are determined along with element concentrations by fitting APXS spectra of geochemical reference materials (GRMs) with the GUAPX code. A quantity K is defined as the ratio between the C/R value determined by Monte Carlo simulation based on the measured element concentrations and the fitted C/R value from the spectrum. To ensure optimally accurate K values, the choice of appropriate GRMs is explored in detail, with attention paid to Rb and Sr, whose characteristic Kα X-ray peaks overlap the Pu Lα <span class="hlt">scatter</span> peaks. The resulting relationship between the ratio K and the overall oxygen fraction is linear. This provides a calibration from which the concentration of additional <span class="hlt">light</span> invisible constituents (ALICs) such as water may be estimated in unknown rock and conglomerate samples. Several GRMs are used as 'unknowns' in order to evaluate the accuracy of ALIC concentrations derived in this manner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21163688','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21163688"><span id="translatedtitle">Study on the ternary mixed ligand complex of palladium(II)-aminophylline-fluorescein sodium by resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>, second-order <span class="hlt">scattering</span> and frequency doubling <span class="hlt">scattering</span> spectrum and its analytical application.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Peili; Liu, Shaopu; Liu, Zhongfang; Hu, Xiaoli</p> <p>2011-01-01</p> <p>The interaction between palladium(II)-aminophylline and fluorescein sodium was investigated by resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>, second-order <span class="hlt">scattering</span> and frequency doubling <span class="hlt">scattering</span> spectrum. In pH 4.4 Britton-Robinson (BR) buffer medium, aminophylline (Ami) reacted with palladium(II) to form chelate cation([Pd(Ami)]2+), which further reacted with fluorescein sodium (FS) to form ternary mixed ligand complex [Pd(Ami)(FS)2]. As a result, resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS), second-order <span class="hlt">scattering</span> (SOS) and frequency doubling <span class="hlt">scattering</span> spectrum (FDS) were enhanced. The maximum <span class="hlt">scattering</span> wavelengths of [Pd(Ami)(FS)2] were located at 300 nm (RRS), 650 nm (SOS) and 304 nm (FDS). The <span class="hlt">scattering</span> intensities were proportional to the Ami concentration in a certain range and the detection limits were 7.3 ng mL(-1) (RRS), 32.9 ng mL(-1) (SOS) and 79.1 ng mL(-1) (FDS), respectively. Based on it, the new simple, rapid, and sensitive <span class="hlt">scattering</span> methods have been proposed to determine Ami in urine and serum samples. Moreover, the formation mechanism of [Pd(Ami)(FS)2] and the reasons for enhancement of RRS were fully discussed. PMID:21163688</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AcSpA..74...36L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AcSpA..74...36L"><span id="translatedtitle">Resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> and resonance non-linear <span class="hlt">scattering</span> method for the determination of aminoglycoside antibiotics with water solubility CdS quantum dots as probe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Zhengwen; Liu, Shaopu; Wang, Lei; Peng, Juanjuan; He, Youqiu</p> <p>2009-09-01</p> <p>In pH 6.6 Britton-Robinson buffer medium, the CdS quantum dots capped by thioglycolic acid could react with aminoglycoside (AGs) antibiotics such as neomycin sulfate (NEO) and streptomycin sulfate (STP) to form the large aggregates by virtue of electrostatic attraction and the hydrophobic force, which resulted in a great enhancement of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) and resonance non-linear <span class="hlt">scattering</span> such as second-order <span class="hlt">scattering</span> (SOS) and frequency doubling <span class="hlt">scattering</span> (FDS). The maximum <span class="hlt">scattering</span> peak was located at 310 nm for RRS, 568 nm for SOS and 390 nm for FDS, respectively. The enhancements of <span class="hlt">scattering</span> intensity (Δ I) were directly proportional to the concentration of AGs in a certain ranges. A new method for the determination of trace NEO and STP using CdS quantum dots probe was developed. The detection limits (3 σ) were 1.7 ng mL -1 (NEO) and 4.4 ng mL -1 (STP) by RRS method, were 5.2 ng mL -1 (NEO) and 20.9 ng mL -1 (STP) by SOS method and were 4.4 ng mL -1 (NEO) and 25.7 ng mL -1 (STP) by FDS method, respectively. The sensitivity of RRS method was the highest. The optimum conditions and influence factors were investigated. In addition, the reaction mechanism was discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730025574&hterms=Reflection+light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DReflection%2Blight','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730025574&hterms=Reflection+light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DReflection%2Blight"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> by cirrus cloud layers.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liou, K.-N.</p> <p>1972-01-01</p> <p>The properties of the reflection, transmission, and absorption of the cirrus cloud layers are calculated under the assumption that the ice crystals in cirrus clouds may be approximated long circular cylinders randomly oriented in space. The phase function, the single <span class="hlt">scattering</span> albedo, and the extinction cross section are obtained on the basis of Liou's (1972) calculations of <span class="hlt">light</span> <span class="hlt">scattering</span> by ice clouds in the visible and infrared. A modified two-stream approximation for radiative transfer is developed and is used to evaluate the radiative properties of the cirrus cloud layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970000423','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970000423"><span id="translatedtitle">Dynamic <span class="hlt">Light</span> <span class="hlt">Scattering</span> From Colloidal Gels</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krall, A. H.; Weitz, David A.</p> <p>1996-01-01</p> <p>We present a brief, preliminary account of the interpretation of dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> from fractal colloidal gels. For small <span class="hlt">scattering</span> angles, and for high initial colloid particle volume fractions, the correlation functions exhibit arrested decay, reflecting the non-ergodic nature of these systems and allowing us to directly determine the elastic modulus of the gels. For smaller initial volume fractions, the correlation functions decay completely. In all cases, the initial decay is not exponential, but is instead described by a stretched exponential. We summarize the principles of a model that accounts for these data and discuss the scaling behavior of the measured parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..885..135S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..885..135S"><span id="translatedtitle">Multiple <span class="hlt">Light</span> <span class="hlt">Scattering</span> Probes of Soft Materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scheffold, Frank</p> <p>2007-02-01</p> <p>I will discuss both static and dynamic properties of diffuse waves. In practical applications the optical properties of colloidal systems play an important role, for example in commercial products such as sunscreen lotions, food (drinks), coatings but also in medicine for example in cataract formation (eye lens turbidity). It is thus of importance to know the key parameters governing optical turbidity from the single to the multiple <span class="hlt">scattering</span> regime. Temporal fluctuations of multiply <span class="hlt">scattered</span> <span class="hlt">light</span> are studied with photon correlation spectroscopy (Diffusing Wave Spectroscopy). This DWS method and its various implementations will be treated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011RScI...82c3501L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011RScI...82c3501L"><span id="translatedtitle">A high-power spatial filter for Thomson <span class="hlt">scattering</span> stray <span class="hlt">light</span> reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Levesque, J. P.; Litzner, K. D.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.</p> <p>2011-03-01</p> <p>The Thomson <span class="hlt">scattering</span> diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure <span class="hlt">scattered</span> <span class="hlt">light</span> from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser <span class="hlt">light</span> to levels which are acceptable for accurate <span class="hlt">Rayleigh</span> calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson <span class="hlt">scattering</span> system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010TePhL..36..358M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010TePhL..36..358M"><span id="translatedtitle">Nonlinear <span class="hlt">scattering</span> of <span class="hlt">light</span> in nanodiamond hydrosol</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mikheev, G. M.; Puzyr', A. P.; Vanyukov, V. V.; Purtov, K. V.; Mogileva, T. N.; Bondar', V. S.</p> <p>2010-04-01</p> <p>The nonlinear <span class="hlt">scattering</span> of <span class="hlt">light</span> under the conditions of optical limiting of nanosecond pulsed laser radiation at a wavelength of 1064 nm in a nanodiamond (ND) hydrosol has been experimentally studied. Superstable hydrosols were obtained from detonation NDs with a modified surface. Using an improved scheme of z scanning, it is shown that a decrease in the optical transmission coefficient of an ND hydrosol under optical limiting conditions is due to enhanced nonlinear <span class="hlt">scattering</span>. It is established that the energy of pulsed radiation <span class="hlt">scattered</span> at a right angle obeys a power law in dependence on the energy density of incident radiation pulses. Hydrosols of detonation NDs with the modified surface exhibit high stability with respect to the periodic laser action at high power density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800023488','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800023488"><span id="translatedtitle">Atmospheric particulate analysis using angular <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hansen, M. Z.</p> <p>1980-01-01</p> <p>Using the <span class="hlt">light</span> <span class="hlt">scattering</span> matrix elements measured by a polar nephelometer, a procedure for estimating the characteristics of atmospheric particulates was developed. A theoretical library data set of <span class="hlt">scattering</span> matrices derived from Mie theory was tabulated for a range of values of the size parameter and refractive index typical of atmospheric particles. Integration over the size parameter yielded the <span class="hlt">scattering</span> matrix elements for a variety of hypothesized particulate size distributions. A least squares curve fitting technique was used to find a best fit from the library data for the experimental measurements. This was used as a first guess for a nonlinear iterative inversion of the size distributions. A real index of 1.50 and an imaginary index of -0.005 are representative of the smoothed inversion results for the near ground level atmospheric aerosol in Tucson.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcSpA.162...93Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcSpA.162...93Y"><span id="translatedtitle">The fluorescence and resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> spectral study and analytical application of cerium (IV) and cefoperazone system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Yusheng; Fu, Shenghui; Xu, Qianying; Yang, Jidong; Hu, Xiaoli; Liu, Shaopu</p> <p>2016-06-01</p> <p>In weak acidic medium of pH 3.5-5.6, Ce(IV) can be reduced by cefoperazone (CPZ) to be Ce(III), which further combined with CPZ to form complex Ce(OH)3CPZ. This complex not only has higher fluorescence than Ce(III), but also results in significant increase of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS), second order <span class="hlt">scattering</span> (SOS) and frequency doubling <span class="hlt">scattering</span> (FDS). The wavelengths of maximum fluorescence exciting and emission are located at 356 nm/349 nm, while the maximum wavelengths of RRS, SOS and FDS are at 312 nm, 550 nm and 390 nm, respectively. The intensity of fluorescence and <span class="hlt">scattering</span> are all linear with the concentration of CPZ in certain conditions. The detection limit of most sensitive RRS method for CPZ is 2.1 ng mL- 1. The optimum conditions for detecting CPZ using RRS method are investigated. The effect of co-existing substances shows that the method has excellent selectivity, especially since other cephalosporins don't have similar reactions. Therefore, it can be achieved to determine CPZ in cephalosporins selectively. The paper also focuses on the reaction mechanism, the consistent and contracture of the resultant. The reasons for enhanced intensity are presumed in the meantime.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2110268','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2110268"><span id="translatedtitle">Bacteriorhodopsin induces a <span class="hlt">light-scattering</span> change in Halobacterium halobium</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>1978-01-01</p> <p>When suspensions of Halobacterium halobium are exposed to bright <span class="hlt">light</span>, the <span class="hlt">light-scattering</span> properties of the bacteria change. This <span class="hlt">light</span>- <span class="hlt">scattering</span> response can produce a transmission decrease of about 1% throughout the red and near-infrared region. The action spectrum for the <span class="hlt">light-scattering</span> response appropriately matches the absorption spectrum of bacteriorhodopsin. The response is eliminated by cyanide p- trifluoro-methoxyphenylhydrazone, a proton ionophore, and by triphenylmethylphosphonium, a membrane permanent cation. A mild hypertonic shock induces a similar <span class="hlt">light-scattering</span> change, suggesting that bright <span class="hlt">light</span> causes the bacteria to shrink about 1% in volume, thereby producing the <span class="hlt">light-scattering</span> response. PMID:32181</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15765711','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15765711"><span id="translatedtitle">Ultraviolet <span class="hlt">Rayleigh</span>-Mie lidar with Mie-<span class="hlt">scattering</span> correction by Fabry-Perot etalons for temperature profiling of the troposphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hua, Dengxin; Uchida, Masaru; Kobayashi, Takao</p> <p>2005-03-01</p> <p>A <span class="hlt">Rayleigh-Mie-scattering</span> lidar system at an eye-safe 355-nm ultraviolet wavelength that is based on a high-spectral-resolution lidar technique is demonstrated for measuring the vertical temperature profile of the troposphere. Two <span class="hlt">Rayleigh</span> signals, which determine the atmospheric temperature, are filtered with two Fabry-Perot etalon filters. The filters are located on the same side of the wings of the <span class="hlt">Rayleigh-scattering</span> spectrum and are optically constructed with a dual-pass optical layout. This configuration achieves a high rejection rate for Mie <span class="hlt">scattering</span> and reasonable transmission for <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>. The Mie signal is detected with a third Fabry-Perot etalon filter, which is centered at the laser frequency. The filter parameters were optimized by numerical calculation; the results showed a Mie rejection of approximately -45 dB, and <span class="hlt">Rayleigh</span> transmittance greater than 1% could be achieved for the two <span class="hlt">Rayleigh</span> channels. A Mie correction method is demonstrated that uses an independent measure of the aerosol <span class="hlt">scattering</span> to correct the temperature measurements that have been influenced by the aerosols and clouds. Simulations and preliminary experiments have demonstrated that the performance of the dual-pass etalon and Mie correction method is highly effective in practical applications. Simulation results have shown that the temperature errors that are due to noise are less than 1 K up to a height of 4 km for daytime measurement for 300 W m(-2) sr(-1) microm(-1) sky brightness with a lidar system that uses 200 mJ of laser energy, a 3.5-min integration time, and a 25-cm telescope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000eaa..bookE4796.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000eaa..bookE4796."><span id="translatedtitle"><span class="hlt">Rayleigh</span> Limit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murdin, P.</p> <p>2000-11-01</p> <p>The theoretical resolving power of a telescope according to a criterion devised by Lord <span class="hlt">Rayleigh</span> (1842-1919). Because of the phenomenon of diffraction the image of a point source of <span class="hlt">light</span> (such as a star) produced even by a perfect optical instrument consists of a central bright spot (the Airy disk) surrounded by concentric dark and <span class="hlt">light</span> rings. If two point sources are very close together, the r...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970000370','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970000370"><span id="translatedtitle">Zeno: Critical Fluid <span class="hlt">Light</span> <span class="hlt">Scattering</span> Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gammon, Robert W.; Shaumeyer, J. N.; Briggs, Matthew E.; Boukari, Hacene; Gent, David A.; Wilkinson, R. Allen</p> <p>1996-01-01</p> <p>The Zeno (Critical Fluid <span class="hlt">Light</span> <span class="hlt">Scattering</span>) experiment is the culmination of a long history of critical fluid <span class="hlt">light</span> <span class="hlt">scattering</span> in liquid-vapor systems. The major limitation to making accurate measurements closer to the critical point was the density stratification which occurs in these extremely compressible fluids. Zeno was to determine the critical density fluctuation decay rates at a pair of supplementary angles in the temperature range 100 mK to 100 (mu)K from T(sub c) in a sample of xenon accurately loaded to the critical density. This paper gives some highlights from operating the instrument on two flights March, 1994 on STS-62 and February, 1996 on STS-75. More detail of the experiment Science Requirements, the personnel, apparatus, and results are displayed on the Web homepage at http://www.zeno.umd.edu.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970001819','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970001819"><span id="translatedtitle">Laser <span class="hlt">Light</span> <span class="hlt">Scattering</span> by Shock Waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Panda, J.; Adamovsky, G.</p> <p>1995-01-01</p> <p><span class="hlt">Scattering</span> of coherent <span class="hlt">light</span> as it propagates parallel to a shock wave, formed in front of a bluff cylindrical body placed in a supersonic stream, is studied experimentally and numerically. Two incident optical fields are considered. First, a large diameter collimated beam is allowed to pass through the shock containing flow. The <span class="hlt">light</span> intensity distribution in the resultant shadowgraph image, measured by a low <span class="hlt">light</span> CCD camera, shows well-defined fringes upstream and downstream of the shadow cast by the shock. In the second situation, a narrow laser beam is brought to a grazing incidence on the shock and the <span class="hlt">scattered</span> <span class="hlt">light</span>, which appears as a diverging sheet from the point of interaction, is visualized and measured on a screen placed normal to the laser path. Experiments are conducted on shocks formed at various free-stream Mach numbers, M, and total pressures, P(sub 0). It is found that the widths of the shock shadows in a shadowgraph image become independent of M and P(sub 0) when plotted against the jump in the refractive index, (Delta)n, created across the shock. The total <span class="hlt">scattered</span> <span class="hlt">light</span> measured from the narrow laser beam and shock interaction also follows the same trend. In the numerical part of the study, the shock is assumed to be a 'phase object', which introduces phase difference between the upstream and downstream propagating parts of the <span class="hlt">light</span> disturbances. For a given shape and (Delta)n of the bow shock the phase and amplitude modulations are first calculated by ray tracing. The wave front is then propagated to the screen using the Fresnet diffraction equation. The calculated intensity distribution, for both of the incident optical fields, shows good agreement with the experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.735a2022B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.735a2022B"><span id="translatedtitle">Influence of convection on the stimulated concentration <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burkhanov, I. S.; Krivokhizha, S. V.; Chaikov, L. L.</p> <p>2016-08-01</p> <p>A non-linear growth of the <span class="hlt">scattering</span> intensity and the frequency shift of the spectral lines of <span class="hlt">scattered</span> <span class="hlt">light</span> close to the half-width of the spontaneous <span class="hlt">scattering</span> in the back <span class="hlt">scattering</span> of <span class="hlt">light</span> in the suspensions of latex nanoparticles in water were found. It proves that we observed a stimulated <span class="hlt">scattering</span> of <span class="hlt">light</span> on the particle concentration variations. Influence of convection is taken into account using Doppler measurements of fluid flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MAR.P1150L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MAR.P1150L"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> measurement of sodium polyacrylate products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lama, Nisha; Norwood, David; Boone, Steven; Massie-Boyer, Valerie</p> <p>2015-03-01</p> <p>In the presentation, we will describe the use of a multi-detector HPLC incorporating the DAWN EOS multi-angle laser <span class="hlt">light</span> <span class="hlt">scattering</span> (MALLS) detector to measure the properties such as molecular weight, RMS radius, contour and persistence length and polydispersity of sodium polyacrylate products. The samples of sodium polyacrylate are used in various industries as thickening agents, coating dispersants, artificial snow, laundry detergent and disposable diapers. Data and results obtained from the experiment will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20212685','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20212685"><span id="translatedtitle">Accuracy of RGD approximation for computing <span class="hlt">light</span> <span class="hlt">scattering</span> properties of diffusing and motile bacteria.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kotlarchyk, M; Chen, S H; Asano, S</p> <p>1979-07-15</p> <p>The quasi-elastic <span class="hlt">light</span> <span class="hlt">scattering</span> has become an established technique for a rapid and quantitative characterization of an average motility pattern of motile bacteria in suspensions. Essentially all interpretations of the measured <span class="hlt">light</span> <span class="hlt">scattering</span> intensities and spectra so far are based on the <span class="hlt">Rayleigh</span>-Gans-Debye (RGD) approximation. Since the range of sizes of bacteria of interest is generally larger than the wavelength of <span class="hlt">light</span> used in the measurement, one is not certain of the justification for the use of the RGD approximation. In this paper we formulate a method by which both the <span class="hlt">scattering</span> intensity and the quasi-elastic <span class="hlt">light</span> <span class="hlt">scattering</span> spectra can be calculated from a rigorous <span class="hlt">scattering</span> theory. For a specific application we study the case of bacteria Escherichia coli (about 1 microm in size) by using numerical solutions of the <span class="hlt">scattering</span> field amplitudes from a prolate spheroid, which is known to simulate optical properties of the bacteria well. We have computed (1) polarized <span class="hlt">scattered</span> <span class="hlt">light</span> intensity vs <span class="hlt">scattering</span> angle for a randomly oriented bacteria population; (2) polarized <span class="hlt">scattered</span> field correlation functions for both a freely diffusing bacterium and for a bacterium undergoing a straight line motion in random directions and with a Maxwellian speed distribution; and (3) the corresponding depolarized <span class="hlt">scattered</span> intensity and field correlation functions. In each case sensitivity of the result to variations of the index of refraction and size of the bacterium is investigated. The conclusion is that within a reasonable range of parameters applicable to E. coli, the accuracy of the RGD is good to within 10% at all angles for the properties (1) and (2), and the depolarized contributions in (3) are generally very small. PMID:20212685</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3601731','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3601731"><span id="translatedtitle">Dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> optical coherence tomography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Jonghwan; Wu, Weicheng; Jiang, James Y.; Zhu, Bo; Boas, David A.</p> <p>2012-01-01</p> <p>We introduce an integration of dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS) and optical coherence tomography (OCT) for high-resolution 3D imaging of heterogeneous diffusion and flow. DLS analyzes fluctuations in <span class="hlt">light</span> <span class="hlt">scattered</span> by particles to measure diffusion or flow of the particles, and OCT uses coherence gating to collect <span class="hlt">light</span> only <span class="hlt">scattered</span> from a small volume for high-resolution structural imaging. Therefore, the integration of DLS and OCT enables high-resolution 3D imaging of diffusion and flow. We derived a theory under the assumption that static and moving particles are mixed within the OCT resolution volume and the moving particles can exhibit either diffusive or translational motion. Based on this theory, we developed a fitting algorithm to estimate dynamic parameters including the axial and transverse velocities and the diffusion coefficient. We validated DLS-OCT measurements of diffusion and flow through numerical simulations and phantom experiments. As an example application, we performed DLS-OCT imaging of the living animal brain, resulting in 3D maps of the absolute and axial velocities, the diffusion coefficient, and the coefficient of determination. PMID:23037374</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87kE511J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87kE511J"><span id="translatedtitle">Identification and mitigation of stray laser <span class="hlt">light</span> in the Thomson <span class="hlt">scattering</span> system on the Madison Symmetric Torus (MST)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobson, C. M.; Borchardt, M. T.; Den Hartog, D. J.; Falkowski, A. F.; Morton, L. A.; Thomas, M. A.</p> <p>2016-11-01</p> <p>The Thomson <span class="hlt">scattering</span> diagnostic on the Madison Symmetric Torus (MST) records excessive levels of stray Nd:YAG laser <span class="hlt">light</span>. Stray <span class="hlt">light</span> saturates the 1064 nm spectral channel in all polychromators, which prevents absolute electron density measurements via <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> calibration. Furthermore, stray <span class="hlt">light</span> contaminates adjacent spectral channels for r/a ≥ 0.75, which renders the diagnostic unable to make electron temperature measurements at these radii. In situ measurements of stray <span class="hlt">light</span> levels during a vacuum vessel vent are used to identify stray <span class="hlt">light</span> sources and strategies for reduction of stray <span class="hlt">light</span> levels. Numerical modeling using Zemax OpticStudio supports these measurements. The model of the vacuum vessel and diagnostic includes synthetic collection optics to enable direct comparison of measured and simulated stray <span class="hlt">light</span> levels. Modeling produces qualitatively similar stray <span class="hlt">light</span> distributions to MST measurements, and quantifies the mitigation effects of stray <span class="hlt">light</span> mitigation strategies prior to implementation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhDT........15Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhDT........15Y"><span id="translatedtitle">Angle-resolved second harmonic <span class="hlt">light</span> <span class="hlt">scattering</span> from colloidal suspensions and second harmonic particle microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Ningping</p> <p>2001-08-01</p> <p>We have carried out two nonlinear optical experiments with colloidal particles. Our first nonlinear optical experiment studied Second-Harmonic Generation (SHG) <span class="hlt">light</span> <span class="hlt">scattering</span> from colloidal suspension. In particular, we measured the angle-resolved second-harmonic generation <span class="hlt">light</span> <span class="hlt">scattering</span> from suspensions of centrosymmetric micron-size polystyrene spheres with surface-adsorbed dye (malachite green). The second-harmonic <span class="hlt">scattering</span> angular profiles differ qualitatively from the linear <span class="hlt">light</span> <span class="hlt">scattering</span> angular profiles of the same particles. We have investigated these radiation patterns using several polarization configurations and particle diameters. We introduce a simple <span class="hlt">Rayleigh</span>-Gans-Debye model to account for the SHG <span class="hlt">scattering</span> anisotropy. The model compares favorably with our experimental data. Our measurements suggest <span class="hlt">scattering</span> anisotropy may be used to isolate particle nonlinear optical effect from other bulk nonlinear optical effects in suspension. Our second nonlinear optical experiment studied the Second-Harmonic Generation (SHG) from single micron-size particles. We built a nonlinear optical microscope for this purpose. We report experimental observations of second harmonic generation from single micron-size polystyrene (PS), silica, and PolyMethylMethAcrylate (PMMA) spheres on flat substrates by SHG microscopy. At low input <span class="hlt">light</span> intensities the SH signals depend quadratically on the intensity of the excitation beam, but at larger input intensities some of the SH signals increase exponentially with increasing input intensity. This exponential enhancement depends on particle size and sphere composition. We describe the experiments, report the observations and provide an approximate analytical framework for understanding our measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730008363&hterms=Staphylococcus+aureus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DStaphylococcus%2Baureus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730008363&hterms=Staphylococcus+aureus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DStaphylococcus%2Baureus"><span id="translatedtitle">Bacterial Identification Using <span class="hlt">Light</span> <span class="hlt">Scattering</span> Measurements: a Preliminary Report</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilkins, J. R.</p> <p>1971-01-01</p> <p>The <span class="hlt">light</span> <span class="hlt">scattering</span> properties of single bacterial cells were examined as a possible means of identification. Three species were studied with streptococcus faecalis exhibiting a unique pattern; the <span class="hlt">light-scattering</span> traces for staphylococcus aureus and escherichia coli were quite similar although differences existed. Based on preliminary investigations, the <span class="hlt">light</span> <span class="hlt">scattering</span> approach appeared promising with additional research needed to include a wide variety of bacterial species, computer capability to handle and analyze data, and expansion of <span class="hlt">light</span> <span class="hlt">scattering</span> theory to include bacterial cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AcSpA.140...15T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AcSpA.140...15T"><span id="translatedtitle">Study on erythrosine-phen-Cd(II) systems by resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>, absorption spectra and their analytical applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Jing; Zhang, Qiqi; Liu, Shaopu; Yang, Jidong; Teng, Ping; Zhu, Jinghui; Qiao, Man; Shi, Ying; Duan, Ruilin; Hu, Xiaoli</p> <p>2015-04-01</p> <p>In pH 7.0-8.0 KH2PO4-Na2HPO4 buffer solution, Cd(II) reacted with 1,10-phenanthroline to form chelate cation [Cd(phen)3]2+, which further reacted with anion of erythrosine to form ternary ion-association complex through electrostatic attraction and hydrophobic effect. This process could result in remarkable absorption spectra change and produce obvious fading reaction at 528 nm. Absorbance change (ΔA) of system was directly proportional to the concentration of Cd(II). Hereby, a highly sensitive spectrophotometric method for the determination of Cd(II) was established. The molar absorption coefficient was 2.29 × 105 L mol-1 cm-1 and the detection limit of Cd(II) was 26.5 ng mL-1. Furthermore, the resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) of this system with two peaks located at 371 and 590 nm enhanced significantly, and second-order <span class="hlt">scattering</span> (SOS) and frequence doubling <span class="hlt">scattering</span> (FDS) of this system changed notably at 640 and 350 nm, respectively. Under the optimum conditions, the <span class="hlt">scattering</span> intensities (ΔIRRS, ΔIDWO-RRS, ΔISOS and ΔIFDS) had good linear relationship with the concentration of Cd(II) in certain ranges. The detection limits of Cd(II) were 1.27 ng mL-1, 1.39 ng mL-1, 4.03 ng mL-1, 5.92 ng mL-1 and 14.7 ng mL-1 for dual-wavelength overlapping resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (DWO-RRS), RRS (371 nm), RRS (590 nm), SOS and FDS, respectively. In addition, the suitable reaction conditions and effects of coexisting substances were investigated. The methods had been successfully applied to the determination of Cd(II) in environmental water samples. The recovery range was between 93.0% and 103.0% and the relative standard deviation (RSD) was between 2.5% and 4.3%. The results were in agreement with those obtained from atomic absorption spectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcSpA.162...75W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcSpA.162...75W"><span id="translatedtitle">A sensitive and selective resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> method for quick detection of avidin using affinity labeling Au nanoparticles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Qi; Huang, Xi; Fu, Xuan; Deng, Huan; Ma, Meihu; Cai, Zhaoxia</p> <p>2016-06-01</p> <p>Avidin is a glycoprotein with antinutritional property, which should be limited in daily food. We developed an affinity biosensor system based on resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) and using affinity biotin labeling Au nanoparticles (AuNPs). This method was selective and sensitive for quick avidin detection due to the avidin-biotin affinitive interaction. Under optimal conditions, RRS intensity of biotin-AuNPs increase linearly with an increasing concentration of avidin from 5 to 160 ng/mL. The lower limit of detection was 0.59 ng/mL. This rapid and selective avidin detection method was used in synthetic samples and egg products with recoveries of between 102.97 and 107.92%, thereby demonstrating the feasible and practical application of this assay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24723431','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24723431"><span id="translatedtitle">A new and highly sensitive resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> assay for lysozyme using aptamer-nanogold as a probe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ma, Lu; Zhang, Xinghui; Liang, Aihui; Liu, Qingye; Jiang, Zhiliang</p> <p>2014-12-01</p> <p>Gold nanoparticles (GN), 10 nm in size, were modified by using lysozyme aptamer (Apt) to obtain a stable Apt–GN probe in pH 8.05 Tris/HCl buffer solutions containing 0.04 mol/L NaCl. Upon addition of lysozyme (LYS), it reacted with the Apt of the probe to form a very stable Apt–LYS complex and to release GNs, which aggregated to form large clusters with a resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) peak at 368 nm. The enhanced peak intensity, ΔI, was linear to the LYS concentration in the range 0.2–5.2 nmol/L, with a detection limit of 0.05 nmol/L. The influence of foreign substance was tested, and the results showed that this RRS method has high selectivity. This Apt–GN RRS method was applied to the analysis of LYS in a real sample, with satisfactory results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24686652','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24686652"><span id="translatedtitle">Daytime measurements of atmospheric temperature profiles (2-15 km) by lidar utilizing <span class="hlt">Rayleigh</span>-Brillouin <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Witschas, Benjamin; Lemmerz, Christian; Reitebuch, Oliver</p> <p>2014-04-01</p> <p>In this Letter, we report on a novel method for measuring atmospheric temperature profiles by lidar during daytime for heights of 2-15.3 km, with a vertical resolution of 0.3-2.2 km, using <span class="hlt">Rayleigh</span>-Brillouin <span class="hlt">scattering</span>. The measurements are performed by scanning a laser (λ=355 nm) over a 12 GHz range and using a Fabry-Pérot interferometer as discriminator. The temperature is derived by using a new analytical line shape model assuming standard atmospheric pressure conditions. Two exemplary temperature profiles resulting from measurements over 14 and 27 min are shown. A comparison with radiosonde temperature measurements shows reasonable agreement. In cloud-free conditions, the temperature difference reaches up to 5 K within the boundary layer, and is smaller than 2.5 K above. The statistical error of the derived temperatures is between 0.15 and 1.5 K. PMID:24686652</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950065253&hterms=microemulsions&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmicroemulsions','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950065253&hterms=microemulsions&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmicroemulsions"><span id="translatedtitle">Improved Optics For Quasi-Elastic <span class="hlt">Light</span> <span class="hlt">Scattering</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cheung, Harry Michael</p> <p>1995-01-01</p> <p>Improved optical train devised for use in <span class="hlt">light-scattering</span> measurements of quasi-elastic <span class="hlt">light</span> <span class="hlt">scattering</span> (QELS) and laser spectroscopy. Measurements performed on solutions, microemulsions, micellular solutions, and colloidal dispersions. Simultaneous measurements of total intensity and fluctuations in total intensity of <span class="hlt">light</span> <span class="hlt">scattered</span> from sample at various angles provides data used, in conjunction with diffusion coefficients, to compute sizes of particles in sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27561996','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27561996"><span id="translatedtitle">On-Resonance Fluorescence, Resonance <span class="hlt">Rayleigh</span> <span class="hlt">Scattering</span>, and Ratiometric Resonance Synchronous Spectroscopy of Molecular- and Quantum Dot-Fluorophores.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Siriwardana, Kumudu; Nettles, Charles B; Vithanage, Buddhini C N; Zhou, Yadong; Zou, Shengli; Zhang, Dongmao</p> <p>2016-09-20</p> <p>Existing studies on molecular fluorescence have almost exclusively been focused on Stokes-shifted fluorescence spectroscopy (SSF) in which the emitted photon is detected at the wavelengths longer than that for the excitation photons. Information on fluorophore on-resonance fluorescence (ORF) and resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) is limited and often problematic due to the complex interplay of the fluorophore photon absorption, ORF emission, RRS, and solvent <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>. Reported herein is a relatively large-scale systematic study on fluorophore ORF and RRS using the conventional UV-vis extinction and SSF measurements in combination with the recently reported ratiometric resonance synchronous spectroscopic (R2S2, pronounced as "R-Two-S-Two") method. A series of fundamental parameters including fluorophore ORF cross sections and quantum yields have been quantified for the first time for a total of 12 molecular and 6 semiconductor quantum dot (QD) fluorophores. All fluorophore spectra comprise a well-defined Gaussian peak with a full width at half-maximum ranging from 4 to 30 nm. However, the RRS features of fluorophores differ drastically. The effect of fluorophore aggregation on its RRS, UV-vis, R2S2, and SSF spectra was also discussed. This work highlights the critical importance of the combined UV-vis extinction, SSF, and R2S2 spectroscopic measurements for material characterizations. The method and insights described in this work can be directly used for improving the reliability of RRS spectroscopic methods in chemical analysis. In addition, it should pave the way for developing novel R2S2-based analytical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/835984','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/835984"><span id="translatedtitle">Modeling <span class="hlt">light</span> <span class="hlt">scattering</span> from diesel soot particles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hull, Patricia; Shepherd, Ian; Hunt, Arlon</p> <p>2002-07-16</p> <p>The Mie model is widely used to analyze <span class="hlt">light</span> <span class="hlt">scattering</span> from particulate aerosols. The Diesel Particle Scatterometer (DPS), for example, determines the size and optical properties of diesel exhaust particles that are characterized by measuring three angle-dependent elements of the Mueller <span class="hlt">scattering</span> matrix. These elements are then fitted using Mie calculations with a Levenburg-Marquardt optimization program. This approach has achieved good fits for most experimental data. However, in many cases, the predicted real and imaginary parts of the index of refraction were less than that for solid carbon. To understand this result and explain the experimental data, we present an assessment of the Mie model by use of a <span class="hlt">light</span> <span class="hlt">scattering</span> model based on the coupled dipole approximation. The results indicate that the Mie calculation can be used to determine the largest dimension of irregularly shaped particles at sizes characteristic of Diesel soot and, for particles of known refractive index, tables can be constructed to determine the average porosity of the particles from the predicted index of refraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EPJWC.11606009M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EPJWC.11606009M&link_type=ABSTRACT"><span id="translatedtitle">Measurement of <span class="hlt">light</span> <span class="hlt">scattering</span> in deep sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maragos, N.; Balasi, K.; Domvoglou, T.; Kiskiras, I.; Lenis, D.; Maniatis, M.; Stavropoulos, G.</p> <p>2016-04-01</p> <p>The deep-sea neutrino telescope in the Mediterranean Sea, being prepared by the KM3NET collaboration, will contain thousands of optical sensors to readout. The accurate knowledge of the optical properties of deep-sea water is of great importance for the neutrino event reconstruction process. In this study we describe our progress in designing an experimental setup and studying a method to measure the parameters describing the absorption and <span class="hlt">scattering</span> characteristics of deep-sea water. Three PMTs will be used to measure in situ the <span class="hlt">scattered</span> <span class="hlt">light</span> emitted from six laser diodes in three different wavelengths covering the Cherenkov radiation spectrum. The technique for the evaluation of the parameters is based on Monte Carlo simulations and our results show that we are able to determine these parameters with satisfying precision.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007OExpr..15.5572G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007OExpr..15.5572G"><span id="translatedtitle"><span class="hlt">Rayleigh</span>-Gans <span class="hlt">scattering</span> approximation: surprisingly useful for understanding backscattering from disk-like particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gordon, Howard R.</p> <p>2007-04-01</p> <p>Recent computations of the backscattering cross section of randomly-oriented disk-like particles (refractive index, 1.20) with small-scale internal structure, using the discrete-dipole approximation (DDA), have been repeated using the <span class="hlt">Rayleigh</span>-Gans approximation (RGA). As long as the thickness of the disks is approximately 20% of the wavelength (or less), the RGA agrees reasonably well quantitatively with the DDA. The comparisons show that the RGA is sufficiently accurate to be useful as a quantitative tool for exploring the backscattering features of disk-like particles with complex structure. It is used here to develop a zeroth-order correction for the neglect of birefringence on modeling the backscattering of detached coccoliths from E. huxleyi.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/14979525','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/14979525"><span id="translatedtitle">Evaporative <span class="hlt">light</span> <span class="hlt">scattering</span> detection of pyrrolizidine alkaloids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaneberg, Brian T; Molyneux, Russell J; Khan, Ikhlas A</p> <p>2004-01-01</p> <p>A reverse-phase high-performance liquid chromatography method utilizing evaporative <span class="hlt">light</span> <span class="hlt">scattering</span> detection (ELSD) has been developed for the simultaneous detection of hepatotoxic pyrrolizidine alkaloids with and without chromophores, namely, riddelliine, riddelliine N-oxide, senecionine, senecionine N-oxide, seneciphylline, retrorsine, integerrimine, lasiocarpine and heliotrine. Pyrrolizidine alkaloids were detected in five plant extracts (Senecio spartioides, S. douglasii var. longilobus, S. jacobaea, S. intergerrimus var. exaltatus and Symphytum officinale). The detection of heliotrine (which does not contain a chromophore) was much improved by ELSD compared with photodiode array detection. PMID:14979525</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22695585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22695585"><span id="translatedtitle"><span class="hlt">Scattering</span> of <span class="hlt">light</span> from metamaterial gratings with finite length.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grünhut, Vivian; Cuevas, Mauro; Depine, Ricardo A</p> <p>2012-06-01</p> <p>Using an integral equation approach based on the <span class="hlt">Rayleigh</span> hypothesis, we investigate the <span class="hlt">scattering</span> of a plane wave at the rough surface of a metamaterial with a finite number of sinusoidal grooves. To show the adequacy of the model, we present results that are in agreement with the predictions of physical optics and that quantitatively reproduce the polarization and angular dependences predicted by the C-formalism for metamaterial gratings with an infinite number of grooves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvA..94b3612Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvA..94b3612Z"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> from dense cold atomic media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Bihui; Cooper, John; Ye, Jun; Rey, Ana Maria</p> <p>2016-08-01</p> <p>We theoretically study the propagation of <span class="hlt">light</span> through a cold atomic medium, where the effects of motion, laser intensity, atomic density, and polarization can all modify the properties of the <span class="hlt">scattered</span> <span class="hlt">light</span>. We present two different microscopic models: the "coherent dipole model" and the "random-walk model", both suitable for modeling recent experimental work done in large atomic arrays in the low-<span class="hlt">light</span>-intensity regime. We use them to compute relevant observables such as the linewidth, peak intensity, and line center of the emitted <span class="hlt">light</span>. We further develop generalized models that explicitly take into account atomic motion. Those are relevant for hotter atoms and beyond the low-intensity regime. We show that atomic motion can lead to drastic dephasing and to a reduction of collective effects, together with a distortion of the line shape. Our results are applicable to model a full gamut of quantum systems that rely on atom-<span class="hlt">light</span> interactions, including atomic clocks, quantum simulators, and nanophotonic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010A%26A...522A..41F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010A%26A...522A..41F"><span id="translatedtitle">Spectral line polarization with angle-dependent partial frequency redistribution. I. A Stokes parameters decomposition for <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frisch, H.</p> <p>2010-11-01</p> <p>Context. The linear polarization of a strong resonance lines observed near the solar limb is created by a multiple-<span class="hlt">scattering</span> process. Partial frequency redistribution (PRD) effects must be accounted for to explain the polarization profiles. The redistribution matrix describing the <span class="hlt">scattering</span> process is a sum of terms, each containing a PRD function multiplied by a <span class="hlt">Rayleigh</span> type phase matrix. A standard approximation made in calculating the polarization is to average the PRD functions over all the <span class="hlt">scattering</span> angles, because the numerical work needed to take the angle-dependence of the PRD functions into account is large and not always needed for reasonable evaluations of the polarization. Aims: This paper describes a Stokes parameters decomposition method, that is applicable in plane-parallel cylindrically symmetrical media, which aims at simplifying the numerical work needed to overcome the angle-average approximation. Methods: The decomposition method relies on an azimuthal Fourier expansion of the PRD functions associated to a decomposition of the phase matrices in terms of the Landi Degl'Innocenti irreducible spherical tensors for polarimetry T^K_Q(i, Ω) (i Stokes parameter index, Ω ray direction). The terms that depend on the azimuth of the <span class="hlt">scattering</span> angle are retained in the phase matrices. Results: It is shown that the Stokes parameters I and Q, which have the same cylindrical symmetry as the medium, can be expressed in terms of four cylindrically symmetrical components I_Q^K (K = Q = 0, K = 2, Q = 0, 1, 2). The components with Q = 1, 2 are created by the angular dependence of the PRD functions. They go to zero at disk center, ensuring that Stokes Q also goes to zero. Each component I_Q^K is a solution to a standard radiative transfer equation. The source term S_Q^K are significantly simpler than the source terms corresponding to I and Q. They satisfy a set of integral equations that can be solved by an accelerated lambda iteration (ALI) method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19422568','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19422568"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> in artificial fog and simulated with <span class="hlt">light</span> <span class="hlt">scattering</span> filter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ikaunieks, Gatis; Colomb, Michéle; Ozolinsh, Maris</p> <p>2009-05-01</p> <p>Disability glare, affecting e.g. road safety at night, may result either from intraocular <span class="hlt">light</span> <span class="hlt">scattering</span> or from external conditions such as fog. Measurements were made of <span class="hlt">light</span> <span class="hlt">scattering</span> in fog and compared with intraocular straylight data for normal eyes and eyes with simulated cataract. All measurements were made with a direct compensation flicker method. To estimate <span class="hlt">light</span> <span class="hlt">scattering</span> levels in fog, straylight measurements were carried in a fog chamber for different densities of fog. Density was characterized by the meteorological term visibility V and ranged from 7 to 25. Test distance for measurements in the fog was constant at 5 m. Cataract eye conditions were simulated by placing a <span class="hlt">light</span> <span class="hlt">scattering</span> polymer dispersed liquid crystal (PDLC) filter with <span class="hlt">scatterers</span> of submicron size in front of the normal eye. All measurements were made using each of three broad-band color stimuli - red, green and blue (produced either with LEDs or a color CRT monitor). Differences were found in both the level and the spectral characteristics of <span class="hlt">scattering</span> under the different conditions. The measured values of the straylight parameter, s, in artificial fog showed no noticeable spectral dependence at any visibility range. Increasing the visibility range caused an exponential decrease in the straylight. Intraocular straylight measured with the clear eye showed an increase at the red and blue ends of the spectrum as compared to the green. Straylight measured using PDLC plates with different transparency levels showed a spectral dependence which decreased with wavelength. The <span class="hlt">scattering</span> introduced by the PDLC plate therefore failed to give a valid simulation of cataract and fog conditions for polychromatic stimuli, due to its erroneous spectral dependence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21313316','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21313316"><span id="translatedtitle">Atom-interferometric studies of <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Beattie, S.; Barrett, B.; Chan, I.; Mok, C.; Kumarakrishnan, A.; Yavin, I.</p> <p>2009-07-15</p> <p>We have used an echo-type atom interferometer that manipulates laser-cooled atoms in a single ground state to investigate the effect of <span class="hlt">light</span> <span class="hlt">scattering</span> from pulsed and continuous-wave <span class="hlt">light</span>. The interferometer uses two off-resonant standing-wave pulses applied at times t=0 and t=T to diffract and recombine momentum states separated by 2({Dirac_h}/2{pi})k at t=2T. Matter wave interference is associated with the formation of a density grating with period {lambda}/2 in the vicinity of this echo time. The grating contrast is measured by recording the intensity of coherently backscattered <span class="hlt">light</span>. The interferometer is perturbed by an additional pulse applied at t=2T-{delta}T or by continuous-wave background <span class="hlt">light</span>. If the additional pulse is a standing wave, the momentum states interfering at t=2T are displaced and the grating contrast can be completely recovered due to constructive interference. In this case, the contrast shows a periodic modulation at the atomic recoil frequency as a function of {delta}T. In a recent work, it was shown that the atomic recoil frequency can be measured easily and precisely when using coherence functions to model the signal shape. This paper provides an alternative description of the signal shape through an analytical calculation of echo formation in the presence of an additional standing-wave pulse. Using this treatment, it is possible to model the effects of spontaneous emission and spatial profile of the laser beam on the signal shape. Additionally, the theory predicts scaling laws as a function of the pulse area and the number of additional standing-wave pulses. These scaling laws are investigated experimentally and can be exploited to improve precision measurements of the atomic recoil frequency. We also show that coherence functions can be used to make a direct measurement of the populations of momentum states associated with the ground state under conditions where the Doppler-broadened velocity distribution of the sample is much</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JQSRT.184...27H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JQSRT.184...27H"><span id="translatedtitle">Sizing aerosolized fractal nanoparticle aggregates through Bayesian analysis of wide-angle <span class="hlt">light</span> <span class="hlt">scattering</span> (WALS) data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huber, Franz J. T.; Will, Stefan; Daun, Kyle J.</p> <p>2016-11-01</p> <p>Inferring the size distribution of aerosolized fractal aggregates from the angular distribution of elastically <span class="hlt">scattered</span> <span class="hlt">light</span> is a mathematically ill-posed problem. This paper presents a procedure for analyzing Wide-Angle <span class="hlt">Light</span> <span class="hlt">Scattering</span> (WALS) data using Bayesian inference. The outcome is probability densities for the recovered size distribution and aggregate morphology parameters. This technique is applied to both synthetic data and experimental data collected on soot-laden aerosols, using a measurement equation derived from <span class="hlt">Rayleigh</span>-Debye-Gans fractal aggregate (RDG-FA) theory. In the case of experimental data, the recovered aggregate size distribution parameters are generally consistent with TEM-derived values, but the accuracy is impaired by the well-known limited accuracy of RDG-FA theory. Finally, we show how this bias could potentially be avoided using the approximation error technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFD.1A011F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFD.1A011F"><span id="translatedtitle">Development of a Burner System and <span class="hlt">Rayleigh</span> <span class="hlt">Scattering</span> Method to Measure Soot Concentration for Diesel-Relevant Fuels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fletcher, Sara; Fisher, Brian</p> <p>2013-11-01</p> <p>Soot, a harmful component of particulate matter, is found in high concentrations in diesel exhaust. This work aims to develop a better understanding of the relationship between chemical structure and soot evolution, which is expected to inform methods to reduce or eliminate soot in diesel combustion. Successful aspects of previous experiments have been combined into a new method to characterize soot formation, growth, and oxidation. Soot is quantified via combined <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> and extinction, using a pulsed 532-nm Nd:YAG laser and sensitive photodetectors. A methane/oxygen diffusion flame serves as a baseline, then species of interest are doped into the fuel stream in low concentration and the change in soot is quantified relative to the base flame. This perturbation method enables study of soot for different species in a flame that has nominally constant global properties. This study focused on fuel components n-heptane and toluene, which have straight-chain and aromatic molecular structures, respectively. Soot was quantified throughout the flame, and it was found that the soot <span class="hlt">scattering</span> signal was significantly higher for toluene than for n-heptane. Analysis of the signals to quantify actual soot concentrations remains a topic of future work. Funding from NSF REU grant 1062611.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27507443','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27507443"><span id="translatedtitle">Highly sensitive determination of antimony in food by resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>-energy transfer between grapheme oxide and I3(.).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wen, Guiqing; Zhang, Xinghui; Li, Yuan; Luo, Yanghe; Liang, Aihui; Jiang, Zhiliang</p> <p>2017-01-01</p> <p>Sb(III) was reduced to SbH3 gas and introduced to the I3(-)-grapheme oxide (GO) or I3(-)-silver nanorod (AgNR)-Victoria blue B (VBB) solutions. Resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> energy transfer (RRS-ET) occurred between the donor GO and the acceptor I3(-) due to the overlap between the absorption peak of I3(-) and RRS peak of GO. When I3(-) was reduced by SbH3, RRS-ET weakened and the RRS intensity enhanced. The increased RRS intensity was linear to Sb concentration in the range of 2.1-376.6μg/L. In the I3(-)-AgNR-VBB solution, I3(-) combined with VBB to form VBB-I3 and there was a weak surface-enhanced Raman <span class="hlt">scattering</span> (SERS) effect. When SbH3 reduced I3(-), the SERS intensity increased due to the release of SERS active VBB. The enhanced SERS intensity was linear for Sb concentration in the range of 8.4-292.9μg/L. The RRS-ET method was applied for determination of Sb in food with satisfactory results. PMID:27507443</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcSpA.161...19T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcSpA.161...19T"><span id="translatedtitle">Double-wavelength overlapping resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> technique for the simultaneous quantitative analysis of three β-adrenergic blockade</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, Xuanping; Yang, Jidong; Li, Qin; Yang, Qiong; Shen, Yizhong</p> <p>2016-05-01</p> <p>Four simple and accurate spectrophotometric methods were proposed for the simultaneous determination of three β-adrenergic blockade, e.g. atenolol, metoprolol and propranolol. The methods were based on the reaction of the three drugs with erythrosine B (EB) in a Britton-Robinson buffer solution at pH 4.6. EB could combine with the drugs to form three ion-association complexes, which resulted in the resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) intensity that is enhanced significantly with new RRS peaks that appeared at 337 nm and 370 nm, respectively. In addition, the fluorescence intensity of EB was also quenched. The enhanced <span class="hlt">scattering</span> intensities of the two peaks and the fluorescence quenched intensity of EB were proportional to the concentrations of the drugs, respectively. What is more, the RRS intensity overlapped with the double-wavelength of 337 nm and 370 nm (so short for DW-RRS) was also proportional to the drugs concentrations. So, a new method with highly sensitive for simultaneous determination of three bisoprolol drugs was established. Finally, the optimum reaction conditions, influencing factors and spectral enhanced mechanism were investigated. The new DW-RRS method has been applied to simultaneously detect the three β-blockers in fresh serum with satisfactory results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JOpt...18g5007A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JOpt...18g5007A"><span id="translatedtitle">Numerical investigation of the <span class="hlt">Rayleigh</span> hypothesis for electromagnetic <span class="hlt">scattering</span> by a particle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Auguié, Baptiste; Somerville, Walter R. C.; Roache, Stanley; Le Ru, Eric C.</p> <p>2016-07-01</p> <p>The validity of the <span class="hlt">Rayleigh</span> hypothesis (RH) has been a long-standing issue in the applicability of the T-matrix method to near-field calculations, and despite numerous theoretical works, the practical consequences for numerical simulations have remained unclear. Such calculations are increasingly important in the field of nano-optics, for which accurate and efficient modeling tools are in high demand. We here tackle this challenge by investigating numerically the convergence behavior of series expansions of the electric field around spheroidal particles, which provides us with unambiguous examples to clarify the conditions of convergence. This study is made possible by the combination of alternative methods to compute near-fields accurately, and crucially, the recent improvements in the calculation of T-matrix elements free from numerical instabilities, as such errors would otherwise obfuscate the intrinsic convergence properties of the field series. The resulting numerical confirmation for the range of validity of the RH, complemented by a better understanding of the convergence behavior of the field expansions, is a crucial step toward future developments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20935759','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20935759"><span id="translatedtitle">Analysis of <span class="hlt">light</span> <span class="hlt">scattering</span> from a cutting tool edge.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, H; Malacara, D</p> <p>1994-07-01</p> <p>The <span class="hlt">scattering</span> of <span class="hlt">light</span> from cutting tools is studied. The contribution of cutting tool edge parameters (height and width) to <span class="hlt">scattering</span> patterns and the influence of side surface roughness on <span class="hlt">scattering</span> patterns are investigated. An angle-limited integrated <span class="hlt">scattering</span> method is developed and analyzed for fast determination of edge parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6186219','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6186219"><span id="translatedtitle">Dense medium radiative transfer theory for two <span class="hlt">scattering</span> layers with a <span class="hlt">Rayleigh</span> distribution of particle sizes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>West, R.; Tsang, Leung; Winebrenner, D.P. )</p> <p>1993-03-01</p> <p>Dense medium radiative transfer theory is applied to a three-layer model consisting of two <span class="hlt">scattering</span> layers overlying a homogeneous half space with a size distribution of particles in each layer. A model with a distribution of sizes gives quite different results than those obtained from a model with a single size. The size distribution is especially important in the low frequency limit when <span class="hlt">scattering</span> is strongly dependent on particle size. The size distribution and absorption characteristics also affect the extinction behavior as a function of fractional volume. Theoretical results are also compared with experimental data. The sizes, permittivities, and densities used in the numerical illustrations are typical values for snow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Prizes+AND+physics&pg=4&id=EJ011035','ERIC'); return false;" href="http://eric.ed.gov/?q=Prizes+AND+physics&pg=4&id=EJ011035"><span id="translatedtitle">A Study of Brownian Motion Using <span class="hlt">Light</span> <span class="hlt">Scattering</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Clark, Noel A.; Lunacek, Joseph H.</p> <p>1969-01-01</p> <p>Describes an apparatus designed to investigate molecular motion by means of <span class="hlt">light</span> <span class="hlt">scattering</span>. <span class="hlt">Light</span> from a He-Ne laser is focused into a cell containing a suspension of polystyrene spheres. The <span class="hlt">scattered</span> <span class="hlt">light</span>, collected on the photosurface of a photomultiplier tube, is analyzed. The apparatus won first prize in Demonstration Lecture Apparatus in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RScI...86i5004W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RScI...86i5004W"><span id="translatedtitle">A novel full-angle scanning <span class="hlt">light</span> <span class="hlt">scattering</span> profiler to quantitatively evaluate forward and backward <span class="hlt">light</span> <span class="hlt">scattering</span> from intraocular lenses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walker, Bennett N.; James, Robert H.; Calogero, Don; Ilev, Ilko K.</p> <p>2015-09-01</p> <p>Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to <span class="hlt">light</span> <span class="hlt">scatter</span>. However, the specific direction that <span class="hlt">light</span> <span class="hlt">scatters</span> makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of <span class="hlt">scattered</span> <span class="hlt">light</span> is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning <span class="hlt">light</span> <span class="hlt">scattering</span> profiler (SLSP) as a novel approach capable of quantitatively evaluating the <span class="hlt">light</span> <span class="hlt">scattering</span> from IOLs with a nearly 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the <span class="hlt">light</span> source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL <span class="hlt">light</span> <span class="hlt">scatter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22482794','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22482794"><span id="translatedtitle">A novel full-angle scanning <span class="hlt">light</span> <span class="hlt">scattering</span> profiler to quantitatively evaluate forward and backward <span class="hlt">light</span> <span class="hlt">scattering</span> from intraocular lenses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Walker, Bennett N.; James, Robert H.; Ilev, Ilko K.; Calogero, Don</p> <p>2015-09-15</p> <p>Glare, glistenings, optical defects, dysphotopsia, and poor image quality are a few of the known deficiencies of intraocular lenses (IOLs). All of these optical phenomena are related to <span class="hlt">light</span> <span class="hlt">scatter</span>. However, the specific direction that <span class="hlt">light</span> <span class="hlt">scatters</span> makes a critical difference between debilitating glare and a slightly noticeable decrease in image quality. Consequently, quantifying the magnitude and direction of <span class="hlt">scattered</span> <span class="hlt">light</span> is essential to appropriately evaluate the safety and efficacy of IOLs. In this study, we introduce a full-angle scanning <span class="hlt">light</span> <span class="hlt">scattering</span> profiler (SLSP) as a novel approach capable of quantitatively evaluating the <span class="hlt">light</span> <span class="hlt">scattering</span> from IOLs with a nearly 360° view. The SLSP method can simulate in situ conditions by controlling the parameters of the <span class="hlt">light</span> source including angle of incidence. This testing strategy will provide a more effective nonclinical approach for the evaluation of IOL <span class="hlt">light</span> <span class="hlt">scatter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AcSpA.126..135T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AcSpA.126..135T"><span id="translatedtitle">Study on the interaction between albendazole and eosin Y by fluorescence, resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> and frequency doubling <span class="hlt">scattering</span> spectra and their analytical applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Fengling; Huang, Wei; Yang, Jidong; Li, Qin</p> <p></p> <p>In pH 3.25-3.35 Britton-Robinson (BR) buffer solution, albendazole (ABZ) could react with eosin Y (EY) to form a 1:1 ion-association complex, which not only results in the quenching of fluorescence, but also resulted in the great enhancement of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) and frequency doubling <span class="hlt">scattering</span> (FDS). Furthermore, a new RRS spectrum will appear, and the maximum RRS wavelength was located at about 356 nm. The detection limit for ABZ were 21.51 ng mL-1 for the fluorophotometry, 6.93 ng mL-1 for the RRS method and 12.89 ng mL-1 for the FDS method. Among them, the RRS method had the highest sensitivity. The experimental conditions were optimized and effects of coexisting substances were evaluated. Meanwhile, the influences of coexisting substances were tested. The methods have been successfully applied to the determination of ABZ in capsules and human urine samples. The composition and structure of the ion-association complex and the reaction mechanism were discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApOpt..51.1586F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApOpt..51.1586F"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> by a multilayered spheroidal particle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farafonov, Victor G.; Voshchinnikov, Nikolai V.</p> <p>2012-04-01</p> <p>The <span class="hlt">light</span> <span class="hlt">scattering</span> problem for a confocal multilayered spheroid has been solved by the extended boundary condition method (EBCM) with a corresponding spheroidal basis. The solution preserves the advantages of the approach applied previously to homogeneous and core-mantle spheroids, i.e. the separation of the radiation fields into two parts and a special choice of scalar potentials for each of the parts. The method is known to be useful in a wide range of the particle parameters. It is particularly efficient for strongly prolate and oblate spheroids. Numerical tests are described. Illustrative calculations have shown that the extinction factors to converge to average values with a growing number of layers and how the extinction vary with a growth of particle porosity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900007772&hterms=Experiment+Light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DExperiment%2BLight','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900007772&hterms=Experiment+Light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DExperiment%2BLight"><span id="translatedtitle">Miniature instrumentation for laser <span class="hlt">light</span> <span class="hlt">scattering</span> experiments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brown, Robert G. W.</p> <p>1989-01-01</p> <p>Traditional optical systems for photon correlation spectroscopy and laser anemometry have relied upon physically large and fairly expensive lasers, bulk-optics such as lenses of a few inches diameter, large mechanical mounts and carefully selected, fragile and bulky photon counting photomultiplier detectors. In some cases, experimental fluid dynamics at a desired position in a flow, perhaps deep inside complex machinery, is physically impossible or very difficult. Similar problems exist with photon correlation spectroscopy, e.g., remote and heterodyne experiments. Various optical and electro optical components were investigated and characterized with the aim of replacing existing photon correlation laser spectroscopy and anemometry techniques in miniaturized form, and with significant cost reduction. Very recently, a range of miniature, modular <span class="hlt">light</span> <span class="hlt">scattering</span> systems were constructed from little solid state optical and electro optical components, and experimentally verified measurement performance comparable to standard lab photon correlation spectroscopy and laser anemometry equipment.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2370..373P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2370..373P"><span id="translatedtitle"><span class="hlt">Light-scattering</span> spectroscopy of native bile</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prygun, Natalya P.; Korolevich, Alexander N.</p> <p>1995-01-01</p> <p><span class="hlt">Light</span> <span class="hlt">scattering</span> spectroscopy (LSS) was used to measure particle sizes in fresh human gallbladder bile of patients with gallstones. The recent experiments suggest the presence of a novel, bile salt-independent, mode of cholesterol transport in saturated human bile. Cholesterol is carried in large phospholipid vesicles with approximate diameter of 75 nm. It was shown that under experimental conditions these vesicles were able to dissolve up to 80% of the biliary cholesterol at low bile salt concentrations. A lecithin lamellar phase has already been suggested as a cholesterol carrier and recently vesicles were reported in model bile solutions and in native bile. Due to its nonperturbing nature, the technique of LLS has in recent years become widely applied to the study of micellar systems and, in particular, has been used to systematically investigate aqueous biliary lipid systems. LSS was employed to characterize the size, shape thermodynamics and interactions of bile salts micelle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20856444','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20856444"><span id="translatedtitle">Effects of asphericity on single-particle polarized <span class="hlt">light</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Spinrad, R W; Brown, J</p> <p>1993-10-20</p> <p>Polarized <span class="hlt">light</span> <span class="hlt">scattering</span> from individual particles has been analyzed to determine the effects of particle shape. Flow cytometric techniques were used on samples of spherical microspheres and naturally occurring marine algae. An analog of the depolarization ratio was obtained by using crossed polarizers in the source and detector of the flow cytometer. Results suggest that differences between the polarized <span class="hlt">light</span> <span class="hlt">scattering</span> of spheres and aspherical particles are not discernible unless the <span class="hlt">scattered</span> intensities are normalized to the forward <span class="hlt">scattering</span>, which is roughly equivalent to particulate cross section. This research indicates that polarized <span class="hlt">light</span> <span class="hlt">scattering</span>, when normalized to particle size, may provide an indication of the extent of asphericity of hydrosols.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EPSC....8.1019K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EPSC....8.1019K"><span id="translatedtitle">Laboratory simulation of <span class="hlt">light</span> <span class="hlt">scattering</span> from regolith surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karand, A.</p> <p>2013-09-01</p> <p>The study of <span class="hlt">light</span> <span class="hlt">scattering</span> by planetary regolith has been and still is a subject of great interest in many different scientific disciplines for many years. Measurement of <span class="hlt">light</span> <span class="hlt">scattered</span> from such surface provide information about the composition and structure of the surface. Here in Assam University, Silchar, India we have set up a laboratory to simulate the <span class="hlt">light</span> <span class="hlt">scattering</span> properties of such surface. Results obtained by the above experiment will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/638296','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/638296"><span id="translatedtitle">Resonant <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> for the determination of trace amounts of mercury (II) with thiocyanate and basic triphenylmethane dyes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, S.; Liu, Z.; Zhou, G.</p> <p>1998-05-01</p> <p>Intense resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) appears when mercury (II) reacts with thiocyanate and a basic triphenylmethane dye (BTPMD), such as crystal violet (CV), ethyl violet (EV), brilliant green (BG), malachite green (MG) or indine green (IG), to form an ion-association complex of the type (BTPMD){sub 2}[Hg(SCN){sub 4}]. The characteristics of RRS spectra of the ion-association complexes and suitable conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of mercury (II) in the range of 0--2.0 {micro}g/25 ml. The RRS methods have very high sensitivities for determination of mercury (II); their detection limits are between 1.68 ng/ml and 6.00 ng/ml on different dye systems. The effects of foreign ions and ways to improve the selectivity were studied. The new highly sensitive methods for the determination of trace amounts of mercury based on the RRS of the ion-association complexes have been developed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16455096','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16455096"><span id="translatedtitle">Incorporation of flow injection analysis or capillary electrophoresis with resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> detection for inorganic ion analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qi, Li; Han, Zhi-qiang; Chen, Yi</p> <p>2006-03-31</p> <p>Resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) has been explored as a detection (RRSD) technique for capillary electrophoresis (CE) or flow injection analysis (FIA) of inorganic ions. The detection was achieved through a <span class="hlt">scattering</span> probe of ion-association complex formed from rhodamine B (Rh B) and iodine. The probe <span class="hlt">scatters</span> strongly at 630 nm when oxidants such as Cr(2)O(7)(2-), MnO(4)(-) and ClO(-) present in a mixed solution of Rh B and iodide. The <span class="hlt">scattering</span> disappears once iodine is reduced by reductants. Oxidant or reductant species in a sample can thus be detected by positive or negative RRS signal. To verify the RRSD, FIA-RRSD was first constructed and continuous measurement of testing samples containing Cr(2)O(7)(2-), MnO(4)(-) and/or ClO(-) was performed. The detection limits reached a level of decade nM and a linear range was found between peak height and concentration at the range of 0.255-2.04microM for Cr(2)O(7)(2-), 0.158-3.16microM for MnO(4)(-), and 1.18-9.43microM for ClO(-), with linear regression coefficients of all above 0.99. The run-to-run relative standard deviation of peak height was less than 3% (n=6). CE-RRSD was then set up and studied, using a capillary of 75microm i.d.x33cm filled with a running buffer of 50mM citrate and 25mM Tris (pH 3.32) and worked under -12kV at room temperature. The CE eluent was at-line conducted into a stream of rhodamine B and iodine flowing inner a wide tube by plugging the capillary outlet into the wide tube. Different mixtures prepared from Cr(2)O(7)(2-), MnO(4)(-) and ClO(-) were successfully separated and detected by the CE-RRSD. PMID:16455096</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4035574','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4035574"><span id="translatedtitle">Angle-resolved <span class="hlt">light</span> <span class="hlt">scattering</span> of individual rod-shaped bacteria based on Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jo, YoungJu; Jung, JaeHwang; Lee, Jee Woong; Shin, Della; Park, HyunJoo; Nam, Ki Tae; Park, Ji-Ho; Park, YongKeun</p> <p>2014-01-01</p> <p>Two-dimensional angle-resolved <span class="hlt">light</span> <span class="hlt">scattering</span> maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span> techniques, the <span class="hlt">light</span> <span class="hlt">scattering</span> patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from −70° to 70°. The measured <span class="hlt">light</span> <span class="hlt">scattering</span> patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic <span class="hlt">light</span> <span class="hlt">scattering</span>. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in <span class="hlt">light</span> <span class="hlt">scattering</span> within bacterial species is related to the cellular dry mass and growth. PMID:24867385</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatSR...4E5090J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatSR...4E5090J"><span id="translatedtitle">Angle-resolved <span class="hlt">light</span> <span class="hlt">scattering</span> of individual rod-shaped bacteria based on Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jo, Youngju; Jung, Jaehwang; Lee, Jee Woong; Shin, Della; Park, Hyunjoo; Nam, Ki Tae; Park, Ji-Ho; Park, Yongkeun</p> <p>2014-05-01</p> <p>Two-dimensional angle-resolved <span class="hlt">light</span> <span class="hlt">scattering</span> maps of individual rod-shaped bacteria are measured at the single-cell level. Using quantitative phase imaging and Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span> techniques, the <span class="hlt">light</span> <span class="hlt">scattering</span> patterns of individual bacteria in four rod-shaped species (Bacillus subtilis, Lactobacillus casei, Synechococcus elongatus, and Escherichia coli) are measured with unprecedented sensitivity in a broad angular range from -70° to 70°. The measured <span class="hlt">light</span> <span class="hlt">scattering</span> patterns are analyzed along the two principal axes of rod-shaped bacteria in order to systematically investigate the species-specific characteristics of anisotropic <span class="hlt">light</span> <span class="hlt">scattering</span>. In addition, the cellular dry mass of individual bacteria is calculated and used to demonstrate that the cell-to-cell variations in <span class="hlt">light</span> <span class="hlt">scattering</span> within bacterial species is related to the cellular dry mass and growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16852700','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16852700"><span id="translatedtitle">Can the <span class="hlt">light</span> <span class="hlt">scattering</span> depolarization ratio of small particles be greater than 1/3?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Khlebtsov, Nikolai G; Melnikov, Andrei G; Bogatyrev, Vladimir A; Dykman, Lev A; Alekseeva, Anna V; Trachuk, Lyubov A; Khlebtsov, Boris N</p> <p>2005-07-21</p> <p>According to the theory of <span class="hlt">light</span> <span class="hlt">scattering</span> by small randomly oriented particles, the depolarized ratio of the <span class="hlt">scattered</span> intensities, I(vh)/I(vv), cannot exceed 1/3. Here we show that this conclusion does not hold for nonspherical plasmon resonant metal particles. Our analysis is based on the <span class="hlt">Rayleigh</span> approximation and the exact T-matrix method as applied to spheroids and circular cylinders with semispherical ends. For small particles, the condition I(vh)/I(vv) >1/3 can be satisfied within the upper left quadrant of the complex relative dielectric permeability Real(eps) < -2 (rods) and within the upper unit semicircle centered at Real(eps) = -1 (disks). For gold nanorods with the axis ratio exceeding 2, the maximal theoretical values I(vh)/I(vv) lie between 1/3 and 3/4 at wavelengths of 550-650 nm. The extinction and static <span class="hlt">light</span> <span class="hlt">scattering</span> spectra (450-850 nm, at 90 degrees degrees) as well as the depolarized ratio of He-Ne laser <span class="hlt">light</span> <span class="hlt">scattering</span> were measured with gold nanospheres (the average diameters of 21, 29, and 46 nm) and nanorods (the longitudinal plasmon resonance peak positions at 655, 692, and 900 nm). The measured depolarization ratios of nanospheres (0.07-0.16) and nanorods (0.3-0.48) are in good agreement with theoretical calculations based on estimations of the average particle size and shape. PMID:16852700</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ApOpt..34.5010W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ApOpt..34.5010W"><span id="translatedtitle">Vesicle sizing by static <span class="hlt">light</span> <span class="hlt">scattering</span>: a Fourier cosine transform approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Jianhong; Hallett, F. Ross</p> <p>1995-08-01</p> <p>A Fourier cosine transform method, based on the <span class="hlt">Rayleigh</span>-Gans-Debye thin-shell approximation, was developed to retrieve vesicle size distribution directly from the angular dependence of <span class="hlt">scattered</span> <span class="hlt">light</span> intensity. Its feasibility for real vesicles was partially tested on <span class="hlt">scattering</span> data generated by the exact Mie solutions for isotropic vesicles. The noise tolerance of the method in recovering unimodal and biomodal distributions was studied with the simulated data. Applicability of this approach to vesicles with weak anisotropy was examined using Mie theory for anisotropic hollow spheres. A primitive theory about the first four moments of the radius distribution about the origin, excluding the mean radius, was obtained as an alternative to the direct retrieval of size distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27409683','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27409683"><span id="translatedtitle">Enhancement of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> in a two-dimensional Fabry-Perot resonator loaded with impurities.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sadreev, Almas F</p> <p>2016-07-01</p> <p>We study wave transmission through a Fabry-Perot resonator (FPR) loaded with point-like impurities. We show both analytically in the framework of the coupled mode theory and numerically that there are two different regimes for transmission dependent on the quality of the FPR mirrors. For low quality, we obtain transmittance very similar to the clean FPR with slightly shifted Lorentz peaks. However, for good quality, the transmittance peaks are strongly reduced and substituted with Gaussian peaks because of multiple <span class="hlt">scattering</span> of waves by each impurity. As a side effect, we observe the angular (channel) conversion in the disordered FPR. We demonstrate that the resonant peaks are dependent on the concentration of impurities to pave a way for resonant measurement of the concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4919638','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4919638"><span id="translatedtitle">Cloaking of solar cell contacts at the onset of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>San Román, Etor; Vitrey, Alan; Buencuerpo, Jerónimo; Prieto, Iván; Llorens, José M.; García-Martín, Antonio; Alén, Benito; Chaudhuri, Anabil; Neumann, Alexander; Brueck, S. R. J.; Ripalda, José M.</p> <p>2016-01-01</p> <p>Electrical contacts on the top surface of solar cells and <span class="hlt">light</span> emitting diodes cause shadow losses. The phenomenon of extraordinary optical transmission through arrays of subwavelength holes suggests the possibility of engineering such contacts to reduce the shadow using plasmonics, but resonance effects occur only at specific wavelengths. Here we describe instead a broadband effect of enhanced <span class="hlt">light</span> transmission through arrays of subwavelength metallic wires, due to the fact that, in the absence of resonances, metal wires asymptotically tend to invisibility in the small size limit regardless of the fraction of the device area taken up by the contacts. The effect occurs for wires more than an order of magnitude thicker than the transparency limit for metal thin films. Finite difference in time domain calculations predict that it is possible to have high cloaking efficiencies in a broadband wavelength range, and we experimentally demonstrate contact shadow losses less than half of the geometric shadow. PMID:27339390</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...628669S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...628669S"><span id="translatedtitle">Cloaking of solar cell contacts at the onset of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>San Román, Etor; Vitrey, Alan; Buencuerpo, Jerónimo; Prieto, Iván; Llorens, José M.; García-Martín, Antonio; Alén, Benito; Chaudhuri, Anabil; Neumann, Alexander; Brueck, S. R. J.; Ripalda, José M.</p> <p>2016-06-01</p> <p>Electrical contacts on the top surface of solar cells and <span class="hlt">light</span> emitting diodes cause shadow losses. The phenomenon of extraordinary optical transmission through arrays of subwavelength holes suggests the possibility of engineering such contacts to reduce the shadow using plasmonics, but resonance effects occur only at specific wavelengths. Here we describe instead a broadband effect of enhanced <span class="hlt">light</span> transmission through arrays of subwavelength metallic wires, due to the fact that, in the absence of resonances, metal wires asymptotically tend to invisibility in the small size limit regardless of the fraction of the device area taken up by the contacts. The effect occurs for wires more than an order of magnitude thicker than the transparency limit for metal thin films. Finite difference in time domain calculations predict that it is possible to have high cloaking efficiencies in a broadband wavelength range, and we experimentally demonstrate contact shadow losses less than half of the geometric shadow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27339390','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27339390"><span id="translatedtitle">Cloaking of solar cell contacts at the onset of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>San Román, Etor; Vitrey, Alan; Buencuerpo, Jerónimo; Prieto, Iván; Llorens, José M; García-Martín, Antonio; Alén, Benito; Chaudhuri, Anabil; Neumann, Alexander; Brueck, S R J; Ripalda, José M</p> <p>2016-01-01</p> <p>Electrical contacts on the top surface of solar cells and <span class="hlt">light</span> emitting diodes cause shadow losses. The phenomenon of extraordinary optical transmission through arrays of subwavelength holes suggests the possibility of engineering such contacts to reduce the shadow using plasmonics, but resonance effects occur only at specific wavelengths. Here we describe instead a broadband effect of enhanced <span class="hlt">light</span> transmission through arrays of subwavelength metallic wires, due to the fact that, in the absence of resonances, metal wires asymptotically tend to invisibility in the small size limit regardless of the fraction of the device area taken up by the contacts. The effect occurs for wires more than an order of magnitude thicker than the transparency limit for metal thin films. Finite difference in time domain calculations predict that it is possible to have high cloaking efficiencies in a broadband wavelength range, and we experimentally demonstrate contact shadow losses less than half of the geometric shadow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27339390','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27339390"><span id="translatedtitle">Cloaking of solar cell contacts at the onset of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>San Román, Etor; Vitrey, Alan; Buencuerpo, Jerónimo; Prieto, Iván; Llorens, José M; García-Martín, Antonio; Alén, Benito; Chaudhuri, Anabil; Neumann, Alexander; Brueck, S R J; Ripalda, José M</p> <p>2016-01-01</p> <p>Electrical contacts on the top surface of solar cells and <span class="hlt">light</span> emitting diodes cause shadow losses. The phenomenon of extraordinary optical transmission through arrays of subwavelength holes suggests the possibility of engineering such contacts to reduce the shadow using plasmonics, but resonance effects occur only at specific wavelengths. Here we describe instead a broadband effect of enhanced <span class="hlt">light</span> transmission through arrays of subwavelength metallic wires, due to the fact that, in the absence of resonances, metal wires asymptotically tend to invisibility in the small size limit regardless of the fraction of the device area taken up by the contacts. The effect occurs for wires more than an order of magnitude thicker than the transparency limit for metal thin films. Finite difference in time domain calculations predict that it is possible to have high cloaking efficiencies in a broadband wavelength range, and we experimentally demonstrate contact shadow losses less than half of the geometric shadow. PMID:27339390</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930060951&hterms=water+filter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwater%2Bfilter','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930060951&hterms=water+filter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwater%2Bfilter"><span id="translatedtitle"><span class="hlt">Rayleigh</span> rejection filters for 193-nm ArF laser Raman spectroscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mckenzie, Robert L.</p> <p>1993-01-01</p> <p>Selected organic absorbers and their solvents are evaluated as spectral filters for the rejection of 193-nm <span class="hlt">Rayleigh</span> <span class="hlt">light</span> associated with the use of an ArF excimer laser for Raman spectroscopy. A simply constructed filter cell filled with 0.5 percent acetone in water and an optical path of 7 mm is shown effectively to eliminate stray <span class="hlt">Rayleigh</span> <span class="hlt">light</span> underlying the Raman spectrum from air while transmitting 60 percent of the Raman <span class="hlt">light</span> <span class="hlt">scattered</span> by O2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22483172','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22483172"><span id="translatedtitle">Recovering the vorticity of a <span class="hlt">light</span> beam after <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Salla, Gangi Reddy Perumangattu, Chithrabhanu; Anwar, Ali; Prabhakar, Shashi; Singh, Ravindra P.</p> <p>2015-07-13</p> <p>We generate optical vortices and <span class="hlt">scatter</span> them through a rough surface. However, the <span class="hlt">scattered</span> <span class="hlt">light</span> passing through a lens shows the same vorticity when probed at the Fourier plane. The vorticity is measured using a nonseparable state of polarization and orbital angular momentum of <span class="hlt">light</span> as it cannot be confirmed by the standard interferometric technique. The observed vorticity is found to be independent of the amount of <span class="hlt">scattered</span> <span class="hlt">light</span> collected. Therefore, vortices can be used as information carriers even in the presence of <span class="hlt">scattering</span> media. The experimental results are well supported by the theoretical results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8011E..45A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8011E..45A"><span id="translatedtitle">Mie <span class="hlt">scattering</span> of <span class="hlt">light</span> with orbital angular momentum by nanoparticles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Acharya, Pramod; Guzmán, Angela M.</p> <p>2011-09-01</p> <p>We generalize Mie <span class="hlt">scattering</span> theory to describe the <span class="hlt">scattering</span> of <span class="hlt">light</span> with orbital angular momentum (OAM). We apply our results to the analysis of <span class="hlt">scattering</span> by gold nanoparticles and compare the angular distribution of the <span class="hlt">scattered</span> <span class="hlt">light</span> for plane waves and <span class="hlt">light</span> with OAM. The multipole expansion for <span class="hlt">scattered</span> OAM waves depends on the localized surface plasmon modes that can couple to incident <span class="hlt">light</span> carrying a well-defined amount of azimuthal charge (or l-number) at a particular wavelength. We study here the properties of Mie <span class="hlt">scattering</span> of OAM waves by nanoparticles located at the beam waist as a function of the size of the particle and of the frequency and content of azimuthal charge of the incident wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20168450','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20168450"><span id="translatedtitle">Quasi-elastic <span class="hlt">light</span> <span class="hlt">scattering</span> from structured particles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, S H; Holz, M; Tartaglia, P</p> <p>1977-01-01</p> <p>We present a formulation by which the <span class="hlt">scattered</span> field correlation function of a nonstationary structured particle can be calculated. Specifically, we consider the case of micron-size bacteria, where the <span class="hlt">Rayleigh</span>- Gans-Debye approximation may be used to evaluate the correlation function. We show that the width of the intensity correlation spectrum (as measured, for example, by the photon correlation technique) exhibits I an oscillatory behavior which is characteristic of the interference pattern produced by the internal structure. Two cases are of interest: diffusion and motility are considered in detail, and some evidence of the predicted behavior is shown from the photon correlation measurement of E. coli bacteria. PMID:20168450</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900007769','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900007769"><span id="translatedtitle">NASA Laser <span class="hlt">Light</span> <span class="hlt">Scattering</span> Advanced Technology Development Workshop, 1988</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meyer, William V. (Editor)</p> <p>1989-01-01</p> <p>The major objective of the workshop was to explore the capabilities of existing and prospective laser <span class="hlt">light</span> <span class="hlt">scattering</span> hardware and to assess user requirements and needs for a laser <span class="hlt">light</span> <span class="hlt">scattering</span> instrument in a reduced gravity environment. The workshop addressed experimental needs and stressed hardware development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=108487&keyword=neon&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=80603303&CFTOKEN=46235300','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=108487&keyword=neon&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=80603303&CFTOKEN=46235300"><span id="translatedtitle">Utility of <span class="hlt">light</span> <span class="hlt">scatter</span> in the morphological analysis of sperm</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>We were able to differentiate the morphologically diverse sperm nuclei of four animal species by using an Ortho flow cytometer to detect the forward <span class="hlt">light</span> <span class="hlt">scatter</span> from a red (helium-neon) laser. Cytograms depicting the axial <span class="hlt">light</span> loss and forward red <span class="hlt">scatter</span> signals revealed uni...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720000160','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720000160"><span id="translatedtitle">Particle detection by a <span class="hlt">light-scattering</span> technique</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kormanyos, S.; Mastroeni, J.</p> <p>1972-01-01</p> <p>Instrument measures concentration of small particles in aqueous medium in terms of amount of <span class="hlt">light</span> <span class="hlt">scattered</span> and degree to which <span class="hlt">light</span> transmission is attenuated. Sensitivity to small particles is optimized because both <span class="hlt">scattered</span> and transmitted illumination levels are detected by photodiodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920062207&hterms=Sargasso+Sea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528Sargasso%2BSea%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920062207&hterms=Sargasso+Sea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2528Sargasso%2BSea%2529"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> by marine heterotrophic bacteria</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ulloa, Osvaldo; Sathyendranath, Shubha; Platt, Trevor; Quinones, Renato A.</p> <p>1992-01-01</p> <p>Mie theory is applied to estimate <span class="hlt">scattering</span> by polydispersions of marine heterotrophic bacteria, and a simple expression is derived for the bacterial <span class="hlt">scattering</span> coefficient. The error incurred in deriving bacterial optical properties by use of the van de Hulst approximations is computed. The <span class="hlt">scattering</span> properties of natural bacterial assemblages in three marine environments, Georges Bank, Northeast Channel, and Sargasso Sea, are assessed by applying Mie theory to field data on bacterial size and abundance. Results are used to examine the potential contribution of bacteria to the <span class="hlt">scattering</span> properties of seawater. The utility of using pigment data to predict the magnitude of <span class="hlt">scattering</span> by bacteria is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22830694','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22830694"><span id="translatedtitle">Mathematical and computational aspects of quaternary liquid mixing free energy measurement using <span class="hlt">light</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wahle, Chris W; Ross, David S; Thurston, George M</p> <p>2012-07-21</p> <p>We provide a mathematical and computational analysis of <span class="hlt">light</span> <span class="hlt">scattering</span> measurement of mixing free energies of quaternary isotropic liquids. In previous work, we analyzed mathematical and experimental design considerations for the ternary mixture case [D. Ross, G. Thurston, and C. Lutzer, J. Chem. Phys. 129, 064106 (2008); C. Wahle, D. Ross, and G. Thurston, J. Chem. Phys. 137, 034201 (2012)]. Here, we review and introduce dimension-free general formulations of the fully nonlinear partial differential equation (PDE) and its linearization, a basis for applying the method to composition spaces of any dimension, in principle. With numerical analysis of the PDE as applied to the <span class="hlt">light</span> <span class="hlt">scattering</span> implied by a test free energy and dielectric gradient combination, we show that values of the <span class="hlt">Rayleigh</span> ratio within the quaternary composition tetrahedron can be used to correctly reconstruct the composition dependence of the free energy. We then extend the analysis to the case of a finite number of data points, measured with noise. In this context the linearized PDE describes the relevant diffusion of information from <span class="hlt">light</span> <span class="hlt">scattering</span> noise to the free energy. The fully nonlinear PDE creates a special set of curves in the composition tetrahedron, collections of which form characteristics of the nonlinear and linear PDEs, and we show that the information diffusion has a time-like direction along the positive normals to these curves. With use of Monte Carlo simulations of <span class="hlt">light</span> <span class="hlt">scattering</span> experiments, we find that for a modest laboratory <span class="hlt">light</span> <span class="hlt">scattering</span> setup, about 100-200 samples and 100 s of measurement time are enough to be able to measure the mixing free energy over the entire quaternary composition tetrahedron, to within an L(2) error norm of 10(-3). The present method can help quantify thermodynamics of quaternary isotropic liquid mixtures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993SPIE.1884...25B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SPIE.1884...25B"><span id="translatedtitle">Dynamic <span class="hlt">light-scattering</span> studies of mucin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bansil, Rama; Pajevic, Sinisa; Cao, Xingxiang; Bhaskar, K. R.; LaMont, Jeffrey T.; Afdhal, Nezham H.; Niu, N.</p> <p>1993-07-01</p> <p>Dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> was applied to study aggregation phenomena in mucin, the glycoprotein responsible for the visco-elastic properties of mucus which is found as a lining on most epithelial cell surfaces. Intensity autocorrelation functions measured on purified mucin solutions under varying experimental conditions were analyzed by Laplace inversion methods. The results showed that at low pH (below 4) solutions of gastric mucin contain very large supra-molecular aggregates, with diffusion constants 100 times slower than those of the 2 X 106 molecular weight glycoprotein of mucin. Similar methods were used to investigate the interaction of gall bladder mucin with cholesterol-phospholipid vesicles. Repeated measurements of the intensity correlation functions after adding mucin to a suspension of vesicles showed a two-fold increase in the hydrodynamic radius of the vesicles over a period of three hours after which the vesicle size stayed constant. Control experiments with latex particles in mucin and vesicles in other proteins showed no change in size, implying that the fusion of vesicles is due to vesicle-mucin interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4707..261K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4707..261K"><span id="translatedtitle">Liposomes by quasielastic <span class="hlt">light</span> <span class="hlt">scattering</span> and spectroturbidimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khlebtsov, Boris N.; Khlebtsov, Nikolai G.; Shchyogolev, Sergei Y.</p> <p>2002-07-01</p> <p>A variant of the experimental implementation of the quasi- elastic <span class="hlt">light</span> <span class="hlt">scattering</span> (QELS) method for determining the average particle size in liposome suspensions in the homodyne mode was considered. The aim of the investigations was to compare the data obtained with the result of a version of the method of spectroturbidimetry (STM) previously developed to determine the size and shell thickness of liposomes. For determination of the corresponding correlation functional, an experimental setup was used that was base don a helium-neon laser with a computer sound card as the analog-digital converter. Monodisperse suspension of latexes and colloidal gold as well as E. coli cell suspension were used as the test objects. The tests showed good accuracy of the QELS determination of the particle diameter d in the region of d < 100. Below this boundary, the accuracy of the particle size determination is limited by the relatively low resolving capacity of the analog-digital converter of the given type. It was established that the results of the determination of the average particle size in liposome polydisperse suspension obtained by QELS and STM were in satisfactory agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..NWS.D1008L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..NWS.D1008L"><span id="translatedtitle">Dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> can determine platelet function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Nathan</p> <p>2011-10-01</p> <p>Platelet transfusions are life-saving procedures for patients who are bleeding or undergoing chemotherapy. The effectiveness of transfusions depends on the number of platelets transfused and the platelet function. Platelet function correlates with proportion of discoid to activated platelets, morphology response to temperature stress, and inversely correlates with microparticle content. ThromboLUX is a novel device that determines platelet function by measuring all of these characteristics using dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS). During periods of stress, such as decreased temperature, cytoskeletal rearrangements will cause normal, discoid platelets to activate and become spiny spheres. The formation of pseudopods of various lengths facilitates the clotting cascade and also increases the apparent size of platelets. ThromboLUX uses a 37-20-37 C temperature cycle that mimics the bleeding, storage, and transfusion process. As the temperature fluctuates, DLS will measure the changing platelet hydrodynamic radius and the size of any microparticles present. ThromboLUX analysis of platelet concentrates in vitro would allow determination of high platelet function units before transfusion and would therefore improve transfusion outcomes and patient safety. This study examined how DLS is able to distinguish between discoid and activated platelets as well as measure the parameters that contribute to high platelet function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JBO....17d0501K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JBO....17d0501K"><span id="translatedtitle">Anisotropic <span class="hlt">light</span> <span class="hlt">scattering</span> of individual sickle red blood cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Youngchan; Higgins, John M.; Dasari, Ramachandra R.; Suresh, Subra; Park, YongKeun</p> <p>2012-04-01</p> <p>We present the anisotropic <span class="hlt">light</span> <span class="hlt">scattering</span> of individual red blood cells (RBCs) from a patient with sickle cell disease (SCD). To measure <span class="hlt">light</span> <span class="hlt">scattering</span> spectra along two independent axes of elongated-shaped sickle RBCs with arbitrary orientation, we introduce the anisotropic Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span> (aFTLS) technique and measured both the static and dynamic anisotropic <span class="hlt">light</span> <span class="hlt">scattering</span>. We observed strong anisotropy in <span class="hlt">light</span> <span class="hlt">scattering</span> patterns of elongated-shaped sickle RBCs along its major axes using static aFTLS. Dynamic aFTLS analysis reveals the significantly altered biophysical properties in individual sickle RBCs. These results provide evidence that effective viscosity and elasticity of sickle RBCs are significantly different from those of the healthy RBCs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050192142','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050192142"><span id="translatedtitle">Laser <span class="hlt">Light</span> <span class="hlt">Scattering</span> with Multiple <span class="hlt">Scattering</span> Suppression Used to Measure Particle Sizes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meyer, William V.; Tin, Padetha; Lock, James A.; Cannell, David S.; Smart, Anthony E.; Taylor, Thomas W.</p> <p>1999-01-01</p> <p>Laser <span class="hlt">light</span> <span class="hlt">scattering</span> is the technique of choice for noninvasively sizing particles in a fluid. The members of the Advanced Technology Development (ATD) project in laser <span class="hlt">light</span> <span class="hlt">scattering</span> at the NASA Lewis Research Center have invented, tested, and recently enhanced a simple and elegant way to extend the concentration range of this standard laboratory particle-sizing technique by several orders of magnitude. With this technique, particles from 3 nm to 3 mm can be measured in a solution. Recently, laser <span class="hlt">light</span> <span class="hlt">scattering</span> evolved to successfully size particles in both clear solutions and concentrated milky-white solutions. The enhanced technique uses the property of <span class="hlt">light</span> that causes it to form tall interference patterns at right angles to the <span class="hlt">scattering</span> plane (perpendicular to the laser beam) when it is <span class="hlt">scattered</span> from a narrow laser beam. Such multiple-<span class="hlt">scattered</span> <span class="hlt">light</span> forms a broad fuzzy halo around the focused beam, which, in turn, forms short interference patterns. By placing two fiber optics on top of each other and perpendicular to the laser beam (see the drawing), and then cross-correlating the signals they produce, only the tall interference patterns formed by singly <span class="hlt">scattered</span> <span class="hlt">light</span> are detected. To restate this, unless the two fiber optics see the same interference pattern, the <span class="hlt">scattered</span> <span class="hlt">light</span> is not incorporated into the signal. With this technique, only singly <span class="hlt">scattered</span> <span class="hlt">light</span> is seen (multiple-<span class="hlt">scattered</span> <span class="hlt">light</span> is rejected) because only singly <span class="hlt">scattered</span> <span class="hlt">light</span> has an interference pattern tall enough to span both of the fiber-optic pickups. This technique is simple to use, easy to align, and works at any angle. Placing a vertical slit in front of the signal collection fibers enhanced this approach. The slit serves as an optical mask, and it significantly shortens the time needed to collect good data by selectively masking out much of the unwanted <span class="hlt">light</span> before cross-correlation is applied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4487338','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4487338"><span id="translatedtitle">A method based on <span class="hlt">light</span> <span class="hlt">scattering</span> to estimate the concentration of virus particles without the need for virus particle standards☆</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Makra, István; Terejánszky, Péter; Gyurcsányi, Róbert E.</p> <p>2015-01-01</p> <p>Most often the determination of the concentration of virus particles is rendered difficult by the availability of proper standards. We have adapted a static <span class="hlt">light</span> <span class="hlt">scattering</span> based method for the quantification of virus particles (shown for poliovirus) without the need of virus particle standards. Instead, as standards, well-characterized polymeric nanoparticle solutions are used. The method is applicable for virus particles acting as <span class="hlt">Rayleigh</span> <span class="hlt">scatterers</span>, i.e., virus particles with equivalent diameters up to ca. 1/10th of the wavelength of the <span class="hlt">scattered</span> monochromatic <span class="hlt">light</span> (∼70 nm diameter). Further limitations may arise if the refractive index of the virus is unavailable or cannot be calculated based on its composition, such as in case of enveloped viruses. The method is especially relevant for preparation of virus particle concentration standards and to vaccine formulations based on attenuated or inactivated virus particles where the classical plaque forming assays cannot be applied. The method consists of: • Measuring the intensity of the <span class="hlt">light</span> <span class="hlt">scattered</span> by viruses suspended in an aqueous solution. • Measuring the intensity of the <span class="hlt">light</span> <span class="hlt">scattered</span> by polymeric nanoparticles of known concentration and comparable size with the investigated virus particle. • The concentration of virus nanoparticles can be calculated based on the two measured <span class="hlt">scattered</span> <span class="hlt">light</span> intensities by knowing the refractive index of the dispersing solution, of the polymer and virus nanoparticles as well as their relative sphere equivalent diameters. PMID:26150976</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22364110','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22364110"><span id="translatedtitle">DUST <span class="hlt">SCATTERING</span> IN TURBULENT MEDIA: CORRELATION BETWEEN THE <span class="hlt">SCATTERED</span> <span class="hlt">LIGHT</span> AND DUST COLUMN DENSITY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Seon, Kwang-Il; Witt, Adolf N.</p> <p>2013-12-01</p> <p>Radiative transfer models in a spherical, turbulent interstellar medium (ISM), in which the photon source is situated at the center, are calculated to investigate the correlation between the <span class="hlt">scattered</span> <span class="hlt">light</span> and the dust column density. The medium is modeled using fractional Brownian motion structures that are appropriate for turbulent ISM. The correlation plot between the <span class="hlt">scattered</span> <span class="hlt">light</span> and optical depth shows substantial <span class="hlt">scatter</span> and deviation from simple proportionality. It was also found that the overall density contrast is smoothed out in <span class="hlt">scattered</span> <span class="hlt">light</span>. In other words, there is an enhancement of the dust-<span class="hlt">scattered</span> flux in low-density regions, while the <span class="hlt">scattered</span> flux is suppressed in high-density regions. The correlation becomes less significant as the <span class="hlt">scattering</span> becomes closer to being isotropic and the medium becomes more turbulent. Therefore, the <span class="hlt">scattered</span> <span class="hlt">light</span> observed in near-infrared wavelengths would show much weaker correlation than the observations in optical and ultraviolet wavelengths. We also find that the correlation plot between <span class="hlt">scattered</span> <span class="hlt">lights</span> at two different wavelengths shows a tighter correlation than that of the <span class="hlt">scattered</span> <span class="hlt">light</span> versus the optical depth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83i3106T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83i3106T"><span id="translatedtitle">Multiangle static and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> in the intermediate <span class="hlt">scattering</span> angle range</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamborini, E.; Cipelletti, L.</p> <p>2012-09-01</p> <p>We describe a <span class="hlt">light</span> <span class="hlt">scattering</span> apparatus based on a novel optical scheme covering the <span class="hlt">scattering</span> angle range 0.5° ⩽ θ ⩽ 25°, an intermediate regime at the frontier between wide angle and small angle setups that is difficult to access by existing instruments. Our apparatus uses standard, readily available optomechanical components. Thanks to the use of a charge-coupled device detector, both static and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> can be performed simultaneously at several <span class="hlt">scattering</span> angles. We demonstrate the capabilities of our apparatus by measuring the <span class="hlt">scattering</span> profile of a variety of samples and the Brownian dynamics of a dilute colloidal suspension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23020361','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23020361"><span id="translatedtitle">Multiangle static and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> in the intermediate <span class="hlt">scattering</span> angle range.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tamborini, E; Cipelletti, L</p> <p>2012-09-01</p> <p>We describe a <span class="hlt">light</span> <span class="hlt">scattering</span> apparatus based on a novel optical scheme covering the <span class="hlt">scattering</span> angle range 0.5° ≤ θ ≤ 25°, an intermediate regime at the frontier between wide angle and small angle setups that is difficult to access by existing instruments. Our apparatus uses standard, readily available optomechanical components. Thanks to the use of a charge-coupled device detector, both static and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> can be performed simultaneously at several <span class="hlt">scattering</span> angles. We demonstrate the capabilities of our apparatus by measuring the <span class="hlt">scattering</span> profile of a variety of samples and the Brownian dynamics of a dilute colloidal suspension. PMID:23020361</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9272E..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9272E..02S"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> characterization of optical components: BRDF, BTDF, and <span class="hlt">scatter</span> losses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schröder, Sven; Finck, Alexander; Katsir, Dina; Zeitner, Uwe; Duparré, Angela</p> <p>2014-11-01</p> <p><span class="hlt">Light</span> <span class="hlt">scattering</span> caused by imperfections of optical components can critically affect the performance of optical systems in terms of losses and image degradation. Because of the numerous potential sources of <span class="hlt">scattering</span> such as roughness, surface and sub-surface defects, bulk inhomogeneities, as well as coatings, <span class="hlt">scattering</span> properties must be carefully specified and measured at the wavelengths of application. Bidirectional Reflectance and Transmittance Distribution Functions (BRDF / BTDF) are used to quantify the angle resolved <span class="hlt">scattering</span> properties. The data can be used as an input for optical engineering software just as FRED, ASAP, ZEMAX for stray <span class="hlt">light</span> modeling. In addition, analyzing the <span class="hlt">scattered</span> <span class="hlt">light</span> can provide valuable information about the relevant imperfections. The presentation provides an overview of instrumentation for <span class="hlt">light</span> <span class="hlt">scattering</span> measurements at wavelengths ranging from the visible to the extreme ultraviolet and the infrared spectral regions. Examples of applications will be discussed ranging from superpolished mirrors to diffraction gratings, interference coatings, and black absorbing coatings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10930524','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10930524"><span id="translatedtitle">Optical characterization of liposomes by right angle <span class="hlt">light</span> <span class="hlt">scattering</span> and turbidity measurement.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Matsuzaki, K; Murase, O; Sugishita, K; Yoneyama, S; Akada, K; Ueha, M; Nakamura, A; Kobayashi, S</p> <p>2000-07-31</p> <p>Liposomes have frequently been used as models of biomembranes or vehicles for drug delivery. However, the systematic characterization of lipid vesicles by right angle <span class="hlt">light</span> <span class="hlt">scattering</span> and turbidity has not been carried out despite the usefulness of such studies for size estimation. In this study, liposomes of various sizes were prepared by sonication and extrusion. The mean cumulant radii of the vesicles were determined by dynamic <span class="hlt">light</span> <span class="hlt">scattering</span>. The lamellarities were estimated based on fluorescence quenching of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)dipalmitoyl-L-alpha-phosph ati dylethanolamine by sodium dithionite. Right angle <span class="hlt">light</span> <span class="hlt">scattering</span> intensity and optical density at 436 nm per unit lipid concentration were measured as a function of vesicle radius. With a vesicle radius < or =100 nm, the optical parameters could be well explained by the <span class="hlt">Rayleigh</span>-Gans-Debye theory in which the liposomes were modeled as homogeneous spheres with mean refractive indices determined by the volume fractions of lipids in vesicles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830055857&hterms=Fluorescent+lights&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DFluorescent%2Blights','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830055857&hterms=Fluorescent+lights&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DFluorescent%2Blights"><span id="translatedtitle">Redistribution - Why half a collision is better than a whole one. [spectra of <span class="hlt">scattered</span> <span class="hlt">light</span> from perturbed atomic system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cooper, J.</p> <p>1983-01-01</p> <p>The study of spectral line shapes has traditionally been mainly concerned with the measurement and interpretation of absorption or emission profiles. Often only the line widths are studied. The present investigation has the objective to evaluate the additional information which can be obtained by <span class="hlt">scattering</span> <span class="hlt">light</span> (usually from a laser) from an atomic system which is being perturbed by collisions. A <span class="hlt">scattering</span> experiment is discussed. The <span class="hlt">scattered</span> <span class="hlt">light</span> consists of two components, a (coherent) <span class="hlt">Rayleigh</span> component and a redistributed (fluorescent) component. In order to obtain the absorption spectrum, questions regarding the probability of photon absorption are considered. By observing the fluorescence subsequent to absorption during a collision it is found possible to obtain information on the evolution of the system from the point of absorption to the completion of the collision. The information on the intracollisional evolution is the justification for the title of the study, namely 'Why half a collision is better than a whole one'.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/985225','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/985225"><span id="translatedtitle">Projection screen having reduced ambient <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sweatt, William C.</p> <p>2010-05-11</p> <p>An apparatus and method for improving the contrast between incident projected <span class="hlt">light</span> and ambient <span class="hlt">light</span> reflected from a projection screen are described. The efficiency of the projection screen for reflection of the projected <span class="hlt">light</span> remains high, while permitting the projection screen to be utilized in a brightly <span class="hlt">lighted</span> room. <span class="hlt">Light</span> power requirements from the projection system utilized may be reduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010018173&hterms=diabetes+mellitus+type&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddiabetes%2Bmellitus%2Btype%2B2','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010018173&hterms=diabetes+mellitus+type&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddiabetes%2Bmellitus%2Btype%2B2"><span id="translatedtitle">Dynamic <span class="hlt">Light</span> <span class="hlt">Scattering</span> of Diabetic Vitreopathy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sebag, J.; Ansari, Rafat R.; Dunker, Stephan; Suh, Kwang I.</p> <p>1999-01-01</p> <p>Diabetes induces pathology throughout the body via nonenzymatic glycation of proteins. Vitreous, which is replete with type 11 collagen, undergoes significant changes in diabetes. The resultant diabetic vitreopathy plays an important role in diabetic retinopathy. Detecting these molecular changes could provide insight into diabetic eye disease as well as molecular effects elsewhere in the body. Human eyes were obtained at autopsy and studied in the fresh, unfixed state. Sclera, choroid, and retina were dissected off the vitreous for dark-field slit microscopy and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS). For the former, the entire vitreous was exposed. For the latter, only a window at the equator was dissected in some specimens, and the anterior segment was removed leaving the posterior lens capsule intact in others. DLS was performed to determine particle sizes at multiple sites 0.5 mm apart, spanning the globe at the equator (window dissections) and along the antero-posterior axis. Dark-field slit microscopy in diabetic subjects detected findings typical of age-related vitreous degeneration, but at much younger ages than nondiabetic controls. Noninvasive DLS measurements found a greater heterogeneity and larger particle sizes in vitreous of subjects with diabetes as compared to age-matched controls. DLS can detect and quantify the early molecular effects that cause vitreous collagen fibrils to cross-link and aggregate. This could provide valuable insight into ocular and systemic effects of hyperglycemia, because the molecular changes in diabetic vitreopathy could serve as an index of such effects throughout the body. In addition to the diagnostic implications, this methodology could provide a rapid, reproducible way to monitor the response to therapy with novel agents intended to prevent the complications of diabetes on a molecular level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptCo.336...24S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptCo.336...24S"><span id="translatedtitle"><span class="hlt">Scattering</span> of polarized Gaussian <span class="hlt">light</span> by a spheroidal particle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Xianming; Xiao, Sai; Ma, Lixiu; Su, Baochen</p> <p>2015-02-01</p> <p><span class="hlt">Light</span> <span class="hlt">scattering</span> by a small particle can produce <span class="hlt">light</span> with polarization characteristics different from those of the incident beam. In this article, we studied the polarized Gaussian beam <span class="hlt">scattered</span> by a spheroidal particle within the generalized Lorenz-Mie theory framework. A theoretical procedure is given to expand an incident Gaussian beam in terms of spheroidal vector wave functions. We studied the single <span class="hlt">scattering</span> properties of a single spheroidal particle with varying aspect ratios and size parameters. Exact analytic solutions are obtained for computing the amplitude matrix and single <span class="hlt">scattering</span> Muller matrix for a single spheroid with normal illumination. The Muller <span class="hlt">scattering</span> matrix elements of a single spheroid are compared between plane wave and Gaussian <span class="hlt">light</span> beam as incident <span class="hlt">light</span> source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55k8002S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55k8002S"><span id="translatedtitle">Origin of <span class="hlt">light</span> <span class="hlt">scattering</span> variations of a latent flaw through <span class="hlt">light</span> <span class="hlt">scattering</span> measurement with applied stress effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakata, Yoshitaro; Terasaki, Nao; Sakai, Kazufumi; Nonaka, Kazuhiro</p> <p>2016-11-01</p> <p>The stress-induced <span class="hlt">light</span> <span class="hlt">scattering</span> method (SILSM) was proposed for inspecting surface to detect polishing induced latent flaws. In this study, in order to clarify the mechanism of the <span class="hlt">light</span> <span class="hlt">scattering</span> intensity variation of latent flaws using SILSM, we have investigated stress effect of <span class="hlt">light</span> <span class="hlt">scattering</span> intensities using polarized <span class="hlt">light</span> system and calculated the reflectance and the retardation using Jones matrix. As the results, we evaluated the change in the birefringence around a tip of a latent flaw between before and after stress were applied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21699309','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21699309"><span id="translatedtitle">Coherent <span class="hlt">light</span> <span class="hlt">scattering</span> from a two-dimensional Mott insulator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weitenberg, Christof; Schauss, Peter; Fukuhara, Takeshi; Cheneau, Marc; Endres, Manuel; Bloch, Immanuel; Kuhr, Stefan</p> <p>2011-05-27</p> <p>We experimentally demonstrate coherent <span class="hlt">light</span> <span class="hlt">scattering</span> from an atomic Mott insulator in a two-dimensional lattice. The far-field diffraction pattern of small clouds of a few hundred atoms was imaged while simultaneously laser cooling the atoms with the probe beams. We describe the position of the diffraction peaks and the scaling of the peak parameters by a simple analytic model. In contrast to Bragg <span class="hlt">scattering</span>, <span class="hlt">scattering</span> from a single plane yields diffraction peaks for any incidence angle. We demonstrate the feasibility of detecting spin correlations via <span class="hlt">light</span> <span class="hlt">scattering</span> by artificially creating a one-dimensional antiferromagnetic order as a density wave and observing the appearance of additional diffraction peaks.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvA..93e3819H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvA..93e3819H"><span id="translatedtitle">Numerical studies of the <span class="hlt">scattering</span> of <span class="hlt">light</span> from a two-dimensional randomly rough interface between two dielectric media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hetland, Ø. S.; Maradudin, A. A.; Nordam, T.; Simonsen, I.</p> <p>2016-05-01</p> <p>The <span class="hlt">scattering</span> of polarized <span class="hlt">light</span> incident from one dielectric medium on its two-dimensional randomly rough interface with a second dielectric medium is studied. A reduced <span class="hlt">Rayleigh</span> equation for the <span class="hlt">scattering</span> amplitudes is derived for the case where p- or s-polarized <span class="hlt">light</span> is incident on this interface, with no assumptions being made regarding the dielectric functions of the media. Rigorous, purely numerical, nonperturbative solutions of this equation are obtained. They are used to calculate the reflectivity and reflectance of the interface, the mean differential reflection coefficient, and the full angular distribution of the intensity of the <span class="hlt">scattered</span> <span class="hlt">light</span>. These results are obtained for both the case where the medium of incidence is the optically less dense medium and in the case where it is the optically more dense medium. Optical analogs of the Yoneda peaks observed in the <span class="hlt">scattering</span> of x rays from metal surfaces are present in the results obtained in the latter case. Brewster <span class="hlt">scattering</span> angles for diffuse <span class="hlt">scattering</span> are investigated, reminiscent of the Brewster angle for flat-interface reflection, but strongly dependent on the angle of incidence. When the contribution from the transmitted field is added to that from the <span class="hlt">scattered</span> field it is found that the results of these calculations satisfy unitarity with an error smaller than 10-4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......299M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......299M"><span id="translatedtitle">Correlating the morphological and <span class="hlt">light</span> <span class="hlt">scattering</span> properties of biological cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moran, Marina</p> <p></p> <p>The <span class="hlt">scattered</span> <span class="hlt">light</span> pattern from a biological cell is greatly influenced by the internal structure and optical properties of the cell. This research project examines the relationships between the morphological and <span class="hlt">scattering</span> properties of biological cells through numerical simulations. The mains goals are: (1) to develop a procedure to analytically model biological cells, (2) to quantitatively study the effects of a range of cell characteristics on the features of the <span class="hlt">light</span> <span class="hlt">scattering</span> patterns, and (3) to classify cells based on the features of their <span class="hlt">light</span> <span class="hlt">scattering</span> patterns. A procedure to create an analytical cell model was developed which extracted structural information from the confocal microscopic images of cells and allowed for the alteration of the cell structure in a controlled and systematic way. The influence of cell surface roughness, nuclear size, and mitochondrial volume density, spatial distribution, size and shape on the <span class="hlt">light</span> <span class="hlt">scattering</span> patterns was studied through numerical simulations of <span class="hlt">light</span> <span class="hlt">scattering</span> using the Discrete Dipole Approximation. It was found that the <span class="hlt">light</span> <span class="hlt">scattering</span> intensity in the <span class="hlt">scattering</span> angle range of 25° to 45° responded to changes in the surface fluctuation of the cell and the range of 90° to 110° was well suited for characterization of mitochondrial density and nuclear size. A comparison of <span class="hlt">light</span> <span class="hlt">scattering</span> pattern analysis methods revealed that the angular distribution of the <span class="hlt">scattered</span> <span class="hlt">light</span> and Gabor filters were most helpful in differentiating between the cell characteristics. In addition, a measured increase in the Gabor energy of the <span class="hlt">light</span> <span class="hlt">scattering</span> patterns in response to an increase in the complexity of the cell models suggested that a complex nuclear structure and mitochondria should be included when modeling biological cells for <span class="hlt">light</span> <span class="hlt">scattering</span> simulations. Analysis of the <span class="hlt">scattering</span> pattern features with Gabor filters resulted in discrimination of the cell models according to cell surface roughness</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18465987','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18465987"><span id="translatedtitle">Measurements of <span class="hlt">light</span> <span class="hlt">scattering</span> in an integrated microfluidic waveguide cytometer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Su, Xuan-Tao; Singh, Kirat; Capjack, Clarence; Petrácek, Jirí; Backhouse, Christopher; Rozmus, Wojciech</p> <p>2008-01-01</p> <p>An integrated microfluidic planar optical waveguide system for measuring <span class="hlt">light</span> <span class="hlt">scattered</span> from a single <span class="hlt">scatterer</span> is described. This system is used to obtain 2D side-<span class="hlt">scatter</span> patterns from single polystyrene microbeads in a fluidic flow. Vertical fringes in the 2D <span class="hlt">scatter</span> patterns are used to infer the location of the 90-deg <span class="hlt">scatter</span> (polar angle). The 2D <span class="hlt">scatter</span> patterns are shown to be symmetrical about the azimuth angle at 90 deg. Wide-angle comparisons between the experimental <span class="hlt">scatter</span> patterns and Mie theory simulations are shown to be in good agreement. A method based on the Fourier transform analysis of the experimental and Mie simulation <span class="hlt">scatter</span> patterns is developed for size differentiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1230250-thomson-scattering-lineshape-fitting-plasma-diagnostics','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1230250-thomson-scattering-lineshape-fitting-plasma-diagnostics"><span id="translatedtitle">Thomson <span class="hlt">Scattering</span> Lineshape Fitting for Plasma Diagnostics</span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p>1994-02-04</p> <p>HFIT30 is used for interpreting lineshape (intensity versus frequency) data from Thomson and <span class="hlt">Rayleigh</span> <span class="hlt">light</span> <span class="hlt">scattering</span> from a plasma, to obtain temperatures and number densities of the component species in the plasma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23455906','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23455906"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> from a moving atom.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Wei</p> <p>2012-12-01</p> <p>In this work, <span class="hlt">scattering</span> of an incident electric field from a moving atom is reexamined classically in two steps: the time-dependent current density created by the field inside the atom is first calculated under the electric-dipole approximation, and is then used to calculate the field <span class="hlt">scattered</span> from the atom. Unlike the conventional frame-hopping method, the present method does not need to treat the Doppler effect as an effect separated from the <span class="hlt">scattering</span> process, and it derives instead of simply uses the Doppler effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23455906','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23455906"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> from a moving atom.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Wei</p> <p>2012-12-01</p> <p>In this work, <span class="hlt">scattering</span> of an incident electric field from a moving atom is reexamined classically in two steps: the time-dependent current density created by the field inside the atom is first calculated under the electric-dipole approximation, and is then used to calculate the field <span class="hlt">scattered</span> from the atom. Unlike the conventional frame-hopping method, the present method does not need to treat the Doppler effect as an effect separated from the <span class="hlt">scattering</span> process, and it derives instead of simply uses the Doppler effect. PMID:23455906</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920001618','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920001618"><span id="translatedtitle">Anomalous <span class="hlt">scattering</span> of <span class="hlt">light</span> on Triton</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Helfenstein, Paul; Lee, Pascal; Mccarthy, Derek; Veverka, Joseph</p> <p>1991-01-01</p> <p>Researchers report here the discovery of an isolated region of anomalously forward <span class="hlt">scattering</span> materials on the surface of Triton. The researchers' best-fit Hapke parameters indicate that regolith particles in the anomalous <span class="hlt">scattering</span> region are not only less backward <span class="hlt">scattering</span>, but also slightly lower in single <span class="hlt">scattering</span> albedo than average materials on Triton's surface. While it might be possible to account for such differences in terms of differences in particle size and transparency, it is also possible that the anomalous region is compositionally distinct from other terrains. It is noteworthy that, for the anomalous region, there exists a distinctively strong spatial correlation between the photometric ratios at different phase angles, and that, relative to other terrains, the anomalous region reddens at a different rate with increasing phase angle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatSR...4E6075B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatSR...4E6075B"><span id="translatedtitle">Bright-White Beetle Scales Optimise Multiple <span class="hlt">Scattering</span> of <span class="hlt">Light</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burresi, Matteo; Cortese, Lorenzo; Pattelli, Lorenzo; Kolle, Mathias; Vukusic, Peter; Wiersma, Diederik S.; Steiner, Ullrich; Vignolini, Silvia</p> <p>2014-08-01</p> <p>Whiteness arises from diffuse and broadband reflection of <span class="hlt">light</span> typically achieved through optical <span class="hlt">scattering</span> in randomly structured media. In contrast to structural colour due to coherent <span class="hlt">scattering</span>, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index <span class="hlt">scattering</span> centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense <span class="hlt">scattering</span> media. Using time-resolved measurements, we show that <span class="hlt">light</span> propagating in the scales of the beetles undergoes pronounced multiple <span class="hlt">scattering</span> that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our <span class="hlt">light</span> transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25123449','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25123449"><span id="translatedtitle">Bright-white beetle scales optimise multiple <span class="hlt">scattering</span> of <span class="hlt">light</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Burresi, Matteo; Cortese, Lorenzo; Pattelli, Lorenzo; Kolle, Mathias; Vukusic, Peter; Wiersma, Diederik S; Steiner, Ullrich; Vignolini, Silvia</p> <p>2014-01-01</p> <p>Whiteness arises from diffuse and broadband reflection of <span class="hlt">light</span> typically achieved through optical <span class="hlt">scattering</span> in randomly structured media. In contrast to structural colour due to coherent <span class="hlt">scattering</span>, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index <span class="hlt">scattering</span> centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense <span class="hlt">scattering</span> media. Using time-resolved measurements, we show that <span class="hlt">light</span> propagating in the scales of the beetles undergoes pronounced multiple <span class="hlt">scattering</span> that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our <span class="hlt">light</span> transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure. PMID:25123449</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4133710','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4133710"><span id="translatedtitle">Bright-White Beetle Scales Optimise Multiple <span class="hlt">Scattering</span> of <span class="hlt">Light</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Burresi, Matteo; Cortese, Lorenzo; Pattelli, Lorenzo; Kolle, Mathias; Vukusic, Peter; Wiersma, Diederik S.; Steiner, Ullrich; Vignolini, Silvia</p> <p>2014-01-01</p> <p>Whiteness arises from diffuse and broadband reflection of <span class="hlt">light</span> typically achieved through optical <span class="hlt">scattering</span> in randomly structured media. In contrast to structural colour due to coherent <span class="hlt">scattering</span>, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index <span class="hlt">scattering</span> centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense <span class="hlt">scattering</span> media. Using time-resolved measurements, we show that <span class="hlt">light</span> propagating in the scales of the beetles undergoes pronounced multiple <span class="hlt">scattering</span> that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our <span class="hlt">light</span> transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure. PMID:25123449</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000eaa..bookE4026.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000eaa..bookE4026."><span id="translatedtitle">Strutt, John William [Lord <span class="hlt">Rayleigh</span>] (1842-1919)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murdin, P.</p> <p>2000-11-01</p> <p>Born in Langford Grove (near Maldon), Essex, England, Nobel prizewinner (1904) for the discovery of argon. He worked in many areas of physics, including electromagnetism and sound; the <span class="hlt">Rayleigh</span> theory of the <span class="hlt">scattering</span> of <span class="hlt">light</span> was the first correct explanation of why the sky is blue....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5178..184P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5178..184P"><span id="translatedtitle">Analytic expression for in-field <span class="hlt">scattered</span> <span class="hlt">light</span> distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peterson, Gary L.</p> <p>2004-01-01</p> <p><span class="hlt">Light</span> that is <span class="hlt">scattered</span> from lenses and mirrors in an optical system produces a halo of stray <span class="hlt">light</span> around bright objects within the field of view. The angular distribution of <span class="hlt">scattered</span> <span class="hlt">light</span> from any one component is usually described by the Harvey model. This paper presents analytic expressions for the <span class="hlt">scattered</span> irradiance at a focal plane from optical components that <span class="hlt">scatter</span> <span class="hlt">light</span> in accordance with the Harvey model. It is found that the irradiance is independent of the location of an optical element within the system, provided the element is not located at or near an intermediate image plane. It is also found that the irradiance has little or no dependence on the size of the element.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16342725','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16342725"><span id="translatedtitle">Experimental observation of universality in depolarized <span class="hlt">light</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Puentes, Graciana; Voigt, Dirk; Aiello, Andrea; Woerdman, J P</p> <p>2005-12-01</p> <p>Experimental results on <span class="hlt">light</span> depolarization due to multimode <span class="hlt">scattering</span> are reported. By means of polarization tomography, we characterize the depolarizing power and the polarization entropy of a broad class of optically <span class="hlt">scattering</span> media and confirm the recently predicted universal behavior of these two quantities [Phys. Rev. Lett. 94, 090406 (2005)].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26699659','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26699659"><span id="translatedtitle">Hierarchical mesoporous silica nanoparticles as superb <span class="hlt">light</span> <span class="hlt">scattering</span> materials.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ryu, Jaehoon; Yun, Juyoung; Lee, Jungsup; Lee, Kisu; Jang, Jyongsik</p> <p>2016-02-01</p> <p>A novel approach to enhance the <span class="hlt">light</span> <span class="hlt">scattering</span> effect was explored by applying hierarchical silica nanoparticles in DSSCs as <span class="hlt">scattering</span> layers. The WSN-incorporated cells showed a PCE value of 9.53% and a PCE enhancement of 30.19% compared with those of the reference cells. PMID:26699659</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SuScT..26j5015C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SuScT..26j5015C"><span id="translatedtitle">Spatial and temporal resolution requirements for quench detection in (RE)Ba2Cu3Ox magnets using <span class="hlt">Rayleigh-scattering</span>-based fiber optic distributed sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chan, W. K.; Flanagan, G.; Schwartz, J.</p> <p>2013-10-01</p> <p>One of the key remaining challenges to safe and reliable operation of large, high temperature superconductor (HTS)-based magnet systems is quench detection and protection. Due to the slow quench propagation in HTS systems, the conventional discrete voltage-tap approach developed for NbTi and Nb3Sn magnets may not be sufficient. In contrast, a distributed temperature profile, generated by a distributed temperature sensor and facilitating continuous monitoring of the temperature at any monitored locations within a magnet with high spatial resolution, may be required. One such distributed temperature sensing option is the use of <span class="hlt">Rayleigh</span>-based fiber optic sensors (FOS), which are immune to electromagnetic interference. The detection of a quench via <span class="hlt">Rayleigh</span>-based FOS relies on converting the spectral shifts in the <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> spectra into temperature variations. As a result, the higher the spatial sampling resolution the larger the data processing volume, and thus the lower the temporal sampling resolution. So, for effective quench detection, which requires the quick and accurate identification of a hot spot, it is important to find a balance between the spatial and temporal resolutions executable on a given data acquisition and processing (DAQ) system. This paper discusses a method for finding an appropriate DAQ technology that matches the characteristic of a superconducting coil, and determining the acceptable resolutions for efficient and safe quench detection. A quench detection algorithm based on distributed temperature sensing is proposed and its implementation challenges are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920066946&hterms=zones+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dzones%2Bocean','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920066946&hterms=zones+ocean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dzones%2Bocean"><span id="translatedtitle">Surface roughness considerations for atmospheric correction of ocean color sensors. I - The <span class="hlt">Rayleigh-scattering</span> component. II - Error in the retrieved water-leaving radiance</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gordon, Howard R.; Wang, Menghua</p> <p>1992-01-01</p> <p>The first step in the Coastal Zone Color Scanner (CZCS) atmospheric-correction algorithm is the computation of the <span class="hlt">Rayleigh-scattering</span> (RS) contribution, L sub r, to the radiance leaving the top of the atmosphere over the ocean. In the present algorithm, L sub r is computed by assuming that the ocean surface is flat. Calculations of the radiance leaving an RS atmosphere overlying a rough Fresnel-reflecting ocean are presented to evaluate the radiance error caused by the flat-ocean assumption. Simulations are carried out to evaluate the error incurred when the CZCS-type algorithm is applied to a realistic ocean in which the surface is roughened by the wind. In situations where there is no direct sun glitter, it is concluded that the error induced by ignoring the <span class="hlt">Rayleigh</span>-aerosol interaction is usually larger than that caused by ignoring the surface roughness. This suggests that, in refining algorithms for future sensors, more effort should be focused on dealing with the <span class="hlt">Rayleigh</span>-aerosol interaction than on the roughness of the sea surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900007774&hterms=Nonimaging+optics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DNonimaging%2Boptics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900007774&hterms=Nonimaging+optics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DNonimaging%2Boptics"><span id="translatedtitle">Design of fiber optic probes for laser <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dhadwal, Harbans S.; Chu, Benjamin</p> <p>1989-01-01</p> <p>A quantitative analysis is presented of the role of optical fibers in laser <span class="hlt">light</span> <span class="hlt">scattering</span>. Design of a general fiber optic/microlens probe by means of ray tracing is described. Several different geometries employing an optical fiber of the type used in lightwave communications and a graded index microlens are considered. Experimental results using a nonimaging fiber optic detector probe show that due to geometrical limitations of single mode fibers, a probe using a multimode optical fiber has better performance, for both static and dynamic measurements of the <span class="hlt">scattered</span> <span class="hlt">light</span> intensity, compared with a probe using a single mode fiber. Fiber optic detector probes are shown to be more efficient at data collection when compared with conventional approaches to measurements of the <span class="hlt">scattered</span> laser <span class="hlt">light</span>. Integration of fiber optic detector probes into a fiber optic spectrometer offers considerable miniaturization of conventional <span class="hlt">light</span> <span class="hlt">scattering</span> spectrometers, which can be made arbitrarily small. In addition static and dynamic measurements of <span class="hlt">scattered</span> <span class="hlt">light</span> can be made within the <span class="hlt">scattering</span> cell and consequently very close to the <span class="hlt">scattering</span> center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910008980','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910008980"><span id="translatedtitle">Evaluation of advanced <span class="hlt">light</span> <span class="hlt">scattering</span> technology for microgravity experiments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fredericks, W. J.; Rosenblum, W. M.</p> <p>1990-01-01</p> <p>The capabilities of modern <span class="hlt">light</span> <span class="hlt">scattering</span> equipment and the uses it might have in studying processes in microgravity are evaluated. Emphasis is on the resolution of polydisperse systems. This choice was made since a major use of <span class="hlt">light</span> <span class="hlt">scattering</span> was expected to be the study of crystal growth of macromolecules in low gravity environments. An evaluation of a modern photon correlation spectrometer and a Mie spectrometer is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1184524','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1184524"><span id="translatedtitle">Measurement of inherent particle properties by dynamic <span class="hlt">light</span> <span class="hlt">scattering</span>: introducing electrorotational <span class="hlt">light</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Prüger, B; Eppmann, P; Donath, E; Gimsa, J</p> <p>1997-01-01</p> <p>Common dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS) methods determine the size and zeta-potential of particles by analyzing the motion resulting from thermal noise or electrophoretic force. Dielectric particle spectroscopy by common microscopic electrorotation (ER) measures the frequency dependence of field-induced rotation of single particles to analyze their inherent dielectric structure. We propose a new technique, electrorotational <span class="hlt">light</span> <span class="hlt">scattering</span> (ERLS). It measures ER in a particle ensemble by a homodyne DLS setup. ER-induced particle rotation is extracted from the initial decorrelation of the intensity autocorrelation function (ACF) by a simple optical particle model. Human red blood cells were used as test particles, and changes of the characteristic frequency of membrane dispersion induced by the ionophore nystatin were monitored by ERLS. For untreated control cells, a rotation frequency of 2 s-1 was induced at the membrane peak frequency of 150 kHz and a field strength of 12 kV/m. This rotation led to a decorrelation of the ACF about 10 times steeper than that of the field free control. For deduction of ERLS frequency spectra, different criteria are discussed. Particle shape and additional field-induced motions like dielectrophoresis and particle-particle attraction do not significantly influence the criteria. For nystatin-treated cells, recalculation of dielectric cell properties revealed an ionophore-induced decrease in the internal conductivity. Although the absolute rotation speed and the rotation sense are not yet directly accessible, ERLS eliminates the tedious microscopic measurements. It offers computerized, statistically significant measurements of dielectric particle properties that are especially suitable for nonbiological applications, e.g., the study of colloidal particles. PMID:9138587</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5642542','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5642542"><span id="translatedtitle">Molecular origin of background <span class="hlt">light</span> in Thomson <span class="hlt">scattering</span> measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McNeill, D.H.</p> <p>1986-06-01</p> <p>The plasma background <span class="hlt">light</span> in Thomson <span class="hlt">scattering</span> measurements is often far higher than expected for a pure hydrogen plasma. The spectral distribution of <span class="hlt">light</span> from three plasmas (duration: 1 ms to steady state; electron density: below 10/sup 12/ to over 10/sup 14/ cm/sup -3/; temperature: below 20 to over 1000 eV) and signal-to-noise and intensity data from the Thomson <span class="hlt">scattering</span> systems used on them are compared with analytic estimates to show that in two of these plasmas molecular <span class="hlt">light</span> dominates the spectrum, while in the other, molecular <span class="hlt">light</span> is present, but bremsstrahlung is usually more intense. Knowledge of the mechanism for background <span class="hlt">light</span> can aid in designing detection systems for Thomson <span class="hlt">scattering</span> and provide information on the neutral species composition and effective charge of the plasma.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19021442','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19021442"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> of semitransparent sintered polytetrafluoroethylene films.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Qinghe; Lee, Bong Jae; Zhang, Zhuomin M; Allen, David W</p> <p>2008-01-01</p> <p>Polytetrafluoroethylene (PTFE) is a strongly <span class="hlt">scattering</span> material and has been regarded to have optical properties similar to biological tissues. In the present study, the bidirectional reflectance distribution function (BRDF) and the bidirectional transmittance distribution function (BTDF) of several PTFE films, with thicknesses from 0.11 to 10 mm, are measured using a laser scatterometer at the wavelength of 635 nm. The directional-hemispherical reflectance (R) and transmittance (T) were obtained by integrating BRDF and BTDF for normal incidence. Comparison of the ratio of the measured R and T with that calculated from the adding-doubling method allows the determination of the reduced <span class="hlt">scattering</span> coefficient. Furthermore, the effect of surface <span class="hlt">scattering</span> is investigated by measuring the polarization-dependent BRDF and BTDF at oblique incidence. By analyzing the measurement uncertainty of BTDF in the near-normal observation angles at normal incidence, the present authors found that the <span class="hlt">scattering</span> coefficient of PTFE should exceed 1200 cm(-1), which is much greater than that of biological tissues. On the other hand, the absorption coefficient of PTFE must be less than 0.01 cm(-1), much smaller than that of biological tissues, a necessary condition to achieve R > or =0.98 with a 10-mm-thick slab. PMID:19021442</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PhDT.......241S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PhDT.......241S"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">Scattering</span> on the High Temperature Superconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Slakey, Francis</p> <p></p> <p>The high temperature superconductors have been examined by the technique of Raman <span class="hlt">scattering</span> in several limits: the insulating phase, the normal and superconducting state of the superconducting phase, and an optically induced metastable phase. In all cases, the analysis and proposed phenomenological models involved either an examination of the inelastic background <span class="hlt">scattering</span> or the phonon excitation spectrum. Specifically, the character, temperature dependence, critical temperature dependence and the copper-oxygen covalency dependence of the inelastic background <span class="hlt">scattering</span> has been studied in all three phases. Analysis of the superconducting phase reveals a marginal Fermi-liquid like character of the electronic polarizability, and a decidedly non-traditional shift of the <span class="hlt">scattering</span> intensity of the electronic excitations at low temperature. On removing oxygen, the system passes through a metal-insulator transition and the inelastic background becomes dominantly magnetic in origin. Examinations of the 'allowed' Raman active phonons in the superconducting phase expose a strong coupling of two modes to the background electronic excitation spectrum, and a dramatic renormalization of these modes below T _{rm c}. Further, two sharply resonant Raman 'forbidden' modes can be bleached out of the spectrum at low temperature with a sufficiently high laser dosage. A transition from this optically induced metastable state to the normal state occurs on warming the crystal back to room temperature. On reducing the oxygen concentration, the coupling strength of the two asymmetric phonons diminishes rapidly, the renormalization effects vanish, and the compound no longer exhibits metastability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApPhL..99g3704L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApPhL..99g3704L"><span id="translatedtitle">Backward elastic <span class="hlt">light</span> <span class="hlt">scattering</span> of malaria infected red blood cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Seungjun; Lu, Wei</p> <p>2011-08-01</p> <p>We investigated the backward <span class="hlt">light</span> <span class="hlt">scattering</span> pattern of healthy and malaria (Plasmodium falciparum) parasitized red blood cells. The spectrum could clearly distinguish between predominant ring stage infected blood cells and healthy blood cells. Further, we found that infected samples mixed with different stages of P. falciparum showed different signals, suggesting that even variance in parasite stages could also be detected by the spectrum. These results together with the backward <span class="hlt">scattering</span> technique suggest the potential of non-invasive diagnosis of malaria through <span class="hlt">light</span> <span class="hlt">scattering</span> of blood cells near the surface of human body, such as using eyes or skin surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.2975..108I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.2975..108I"><span id="translatedtitle">Fiber optic <span class="hlt">light-scattering</span> measurement system for evaluation of embryo viability: <span class="hlt">light-scattering</span> characteristics from live mouse embryo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Itoh, Harumi; Arai, Tsunenori; Kikuchi, Makoto</p> <p>1997-06-01</p> <p>We measured angular distribution of the <span class="hlt">light</span> <span class="hlt">scattering</span> from live mouse embryo with 632.8nm in wavelength to evaluate the embryo viability. We aim to measure the mitochondrial density in human embryo which have relation to the embryo viability. We have constructed the <span class="hlt">light</span> <span class="hlt">scattering</span> measurement system to detect the mitochondrial density non-invasively. We have employed two optical fibers for the illumination and sensing to change the angle between these fibers. There were two dips on the <span class="hlt">scattering</span> angular distribution from the embryo. These dips existed on 30 and 85 deg. We calculated the <span class="hlt">scattering</span> angular pattern by Mie theory to fit the measured <span class="hlt">scattering</span> estimated <span class="hlt">scattering</span> size and density. The best fitting was obtained when the particle size and density were 0.9 micrometers and 1010 particles per ml, respectively. These values coincided with the approximated values of mitochondrial in the embryo. The measured <span class="hlt">light</span> <span class="hlt">scattering</span> may mainly originated from mitochondria in spite of the existence of the various <span class="hlt">scattering</span> particles in the embryo. Since our simple <span class="hlt">scattering</span> measurement may offer the mitochondrial density in the embryo, it might become the practical method of human embryo on in vitro fertilization-embryo transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21388746','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21388746"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> by ultracold atoms in an optical lattice</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rist, Stefan; Menotti, Chiara; Morigi, Giovanna</p> <p>2010-01-15</p> <p>We investigate theoretically <span class="hlt">light</span> <span class="hlt">scattering</span> of photons by ultracold atoms in an optical lattice in the linear regime. A full quantum theory for the atom-photon interactions is developed as a function of the atomic state in the lattice along the Mott-insulator-superfluid phase transition, and the photonic-<span class="hlt">scattering</span> cross section is evaluated as a function of the energy and of the direction of emission. The predictions of this theory are compared with the theoretical results of a recent work on Bragg <span class="hlt">scattering</span> in time-of-flight measurements [A.M. Rey et al., Phys. Rev. A 72, 023407 (2005)]. We show that, when performing Bragg spectroscopy with <span class="hlt">light</span> <span class="hlt">scattering</span>, the photon recoil gives rise to an additional atomic site-to-site hopping, which can interfere with ordinary tunneling of matter waves and can significantly affect the photonic-<span class="hlt">scattering</span> cross section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AcSpA.122...75T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AcSpA.122...75T"><span id="translatedtitle">Study on interaction between palladium(ІІ)-Linezolid chelate with eosin by resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>, second order of <span class="hlt">scattering</span> and frequency doubling <span class="hlt">scattering</span> methods using Taguchi orthogonal array design</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thakkar, Disha; Gevriya, Bhavesh; Mashru, R. C.</p> <p>2014-03-01</p> <p>Linezolid reacted with palladium to form 1:1 binary cationic chelate which further reacted with eosin dye to form 1:1 ternary ion association complex at pH 4 of Walpole's acetate buffer in the presence of methyl cellulose. As a result not only absorption spectra were changed but Resonance <span class="hlt">Rayleigh</span> <span class="hlt">Scattering</span> (RRS), Second-order <span class="hlt">Scattering</span> (SOS) and Frequency Doubling <span class="hlt">Scattering</span> (FDS) intensities were greatly enhanced. The analytical wavelengths of RRS, SOS and FDS (λex/λem) of ternary complex were located at 538 nm/538 nm, 240 nm/480 nm and 660 nm/330 nm, respectively. The linearity range for RRS, SOS and FDS methods were 0.01-0.5 μg mL-1, 0.1-2 μg mL-1 and 0.2-1.8 μg mL-1, respectively. The sensitivity order of three methods was as RRS > SOS > FDS. Accuracy of all methods were determined by recovery studies and showed recovery between 98% and 102%. Intraday and inter day precision were checked for all methods and %RSD was found to be less than 2 for all methods. The effects of foreign substances were tested on RRS method and it showed the method had good selectivity. For optimization of process parameter, Taguchi orthogonal array design L8(24) was used and ANOVA was adopted to determine the statistically significant control factors that affect the <span class="hlt">scattering</span> intensities of methods. The reaction mechanism, composition of ternary ion association complex and reasons for <span class="hlt">scattering</span> intensity enhancement was discussed in this work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27136777','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27136777"><span id="translatedtitle">Simulation of <span class="hlt">light</span> <span class="hlt">scattering</span> from exoskeletons of scarab beetles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Valyukh, Sergiy; Arwin, Hans; Järrendahl, Kenneth</p> <p>2016-03-21</p> <p>An approach for simulation of <span class="hlt">light</span> <span class="hlt">scattering</span> from beetles exhibiting structural colors originating from periodic helicoidal structures is presented. Slight irregularities of the periodic structure in the exoskeleton of the beetles are considered as a major cause of <span class="hlt">light</span> <span class="hlt">scattering</span>. Two sources of <span class="hlt">scattering</span> are taken into account: surface roughness and volume non-uniformity. The Kirchhoff approximation is applied to simulate the effect of surface roughness. To describe volume non-uniformity, the whole structure is modeled as a set of domains distributed in space in different orientations. Each domain is modeled as an ideal uniformly twisted uniaxial medium and differs from each other by the pitch. Distributions of the domain parameters are assumed to be Gaussian. The analysis is performed using the Mueller matrix formalism which, in addition to spectral and spatial characteristics, also provides polarization properties of the <span class="hlt">scattered</span> <span class="hlt">light</span>. PMID:27136777</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AIPC..992...75P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008AIPC..992...75P&link_type=ABSTRACT"><span id="translatedtitle">Study of <span class="hlt">Light</span> <span class="hlt">Scattering</span> in the Human Eye</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perez, I. Kelly; Bruce, N. C.; Valdos, L. R. Berriel</p> <p>2008-04-01</p> <p>In this paper we present a numerical model of the human eye to be used in studies of the <span class="hlt">scattering</span> of <span class="hlt">light</span> in different components of the eye's optical system. Different parts of the eye are susceptible to produce <span class="hlt">scattering</span> for different reasons; age, illness or injury. For example, cataracts can appear in the human lens or injuries or fungi can appear on the cornea. The aim of the study is to relate the backscattered <span class="hlt">light</span>, which is what doctors measure or detect, to the forward <span class="hlt">scattered</span> <span class="hlt">light</span>, which is what affects the patient's vision. We present the model to be used, the raytrace procedure and some preliminary results for the image on the retina without <span class="hlt">scattering</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18033557','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18033557"><span id="translatedtitle">Polar nephelometer for <span class="hlt">light-scattering</span> measurements of ice crystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barkey, B; Liou, K N</p> <p>2001-02-15</p> <p>We report on a small, lightweight polar nephelometer for the measurement of the <span class="hlt">light-scattering</span> properties of cloud particles, specifically designed for use on a balloonborne platform in cirrus cloud conditions. The instrument consists of 33 fiber-optic <span class="hlt">light</span> guides positioned in a two-dimensional plane from 5 degrees to 175 degrees that direct the <span class="hlt">scattered</span> <span class="hlt">light</span> to photodiode detectors-amplifier units. The system uses an onboard computer and data acquisition card to collect and store the measured signals. The instrument's calibration is tested by measurement of <span class="hlt">light</span> <span class="hlt">scattered</span> into a two-dimensional plane from small water droplets generated by an ultrasonic humidifier. Excellent comparisons between the measured water-droplet <span class="hlt">scattering</span> properties and expectations generated by Mie calculation are shown. The measured <span class="hlt">scattering</span> properties of ice crystals generated in a cold chamber also compare reasonably well with the theoretical results based on calculations from a unified theory of <span class="hlt">light</span> <span class="hlt">scattering</span> by ice crystals that use the particle size distribution measured in the chamber. PMID:18033557</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18033557','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18033557"><span id="translatedtitle">Polar nephelometer for <span class="hlt">light-scattering</span> measurements of ice crystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barkey, B; Liou, K N</p> <p>2001-02-15</p> <p>We report on a small, lightweight polar nephelometer for the measurement of the <span class="hlt">light-scattering</span> properties of cloud particles, specifically designed for use on a balloonborne platform in cirrus cloud conditions. The instrument consists of 33 fiber-optic <span class="hlt">light</span> guides positioned in a two-dimensional plane from 5 degrees to 175 degrees that direct the <span class="hlt">scattered</span> <span class="hlt">light</span> to photodiode detectors-amplifier units. The system uses an onboard computer and data acquisition card to collect and store the measured signals. The instrument's calibration is tested by measurement of <span class="hlt">light</span> <span class="hlt">scattered</span> into a two-dimensional plane from small water droplets generated by an ultrasonic humidifier. Excellent comparisons between the measured water-droplet <span class="hlt">scattering</span> properties and expectations generated by Mie calculation are shown. The measured <span class="hlt">scattering</span> properties of ice crystals generated in a cold chamber also compare reasonably well with the theoretical results based on calculations from a unified theory of <span class="hlt">light</span> <span class="hlt">scattering</span> by ice crystals that use the particle size distribution measured in the chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20448766','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20448766"><span id="translatedtitle"><span class="hlt">Scattering</span> of <span class="hlt">light</span> by molecules over a rough surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Long, Maureen; Khine, Michelle; Kim, Arnold D</p> <p>2010-05-01</p> <p>We present a theory for the multiple <span class="hlt">scattering</span> of <span class="hlt">light</span> by obstacles situated over a rough surface. This problem is important for applications in biological and chemical sensors. To keep the formulation of this theory simple, we study scalar waves. This theory requires knowledge of the <span class="hlt">scattering</span> operator (t-matrix) for each of the obstacles as well as the reflection operator for the rough surface. The <span class="hlt">scattering</span> operator gives the field <span class="hlt">scattered</span> by the obstacle due to an exciting field incident on the <span class="hlt">scatterer</span>. The reflection operator gives the field reflected by the rough surface due to an exciting field incident on the rough surface. We apply this general theory for the special case of point <span class="hlt">scatterers</span> and a slightly rough surface with homogeneous Dirichlet and Neumann boundary conditions. We show examples that demonstrate the utility of this theory. PMID:20448766</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24785964','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24785964"><span id="translatedtitle">Multiple <span class="hlt">scattering</span> of polarized <span class="hlt">light</span>: influence of absorption.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hohmann, A; Voit, F; Schäfer, J; Kienle, A</p> <p>2014-06-01</p> <p>This work continues previous research about multiple <span class="hlt">scattering</span> of polarized <span class="hlt">light</span> propagation in turbid media, putting emphasis on the imaginary part of the <span class="hlt">scatterers</span>' complex refractive index. The whole angle-dependent Müller matrix is evaluated by comparing results of a polarization sensitive radiative transfer solution to Maxwell theory. Turbid media of defined <span class="hlt">scatterer</span> concentrations are modelled in three dimensions by sphere ensembles kept inside a cubic or spherical simulation volume. This study addresses the impact of absorption on polarization characteristics for selected media from low to high absorption. Besides that, effects caused by multiple and dependent <span class="hlt">scattering</span> are shown for increasing volume concentration. In this context some unique properties associated with multiple <span class="hlt">scattering</span> and absorption are pointed out. Further, <span class="hlt">scattering</span> results in two dimensions are compared for examples of infinite parallel cylinders of high absorption and perpendicularly incident plane waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JPhCS.250a2063X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JPhCS.250a2063X"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> in optical CT scanning of Presage dosimeters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Y.; Adamovics, J.; Cheeseborough, J. C.; Chao, K. S.; Wuu, C. S.</p> <p>2010-11-01</p> <p>The intensity of the <span class="hlt">scattered</span> <span class="hlt">light</span> from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS" optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of <span class="hlt">scattered</span> photons was found to be more than 1% of the primary <span class="hlt">light</span> signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the <span class="hlt">scattered</span> <span class="hlt">light</span> increases with increasing <span class="hlt">light</span> attenuations and/or absorptions in the dosimeters. The <span class="hlt">scattered</span> <span class="hlt">light</span> at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the <span class="hlt">light</span> <span class="hlt">scattering</span> in different types of optical CT scanners are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JQSRT.119...53S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JQSRT.119...53S"><span id="translatedtitle">Impact of morphological parameters onto simulated <span class="hlt">light</span> <span class="hlt">scattering</span> patterns</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Skorupski, Krzysztof; Mroczka, Janusz; Riefler, Norbert; Oltmann, Hergen; Will, Stefan; Wriedt, Thomas</p> <p>2013-04-01</p> <p>We have investigated the impact of the variation of various parameters of fractal aggregates on simulated <span class="hlt">light</span> <span class="hlt">scattering</span> patterns. Static <span class="hlt">light</span> <span class="hlt">scattering</span> is commonly used to measure soot in a flame and such a study could help to improve experimental approaches. Aggregate models, used for our <span class="hlt">light</span> <span class="hlt">scattering</span> simulations, are based on real soot structures that can be found under laboratory conditions in a premixed ethane/air flame (McKenna-type burner, equivalence ratio ϕ=2.5). Our work was not focused on modeling and analysis of aggregates that are typically encountered in the atmosphere, therefore the results might be of limited interest to climate scientists. In our study, the variation of all parameters that enter into the standard fractal equation were investigated. Additionally effects when varying the overlap of primary particles, the incident wavelength and the complex refractive index are discussed. For numerical simulations two different codes were used, the T-Matrix (when particles are in point contact) and the DDScat program (which is capable of performing <span class="hlt">light</span> <span class="hlt">scattering</span> simulations by overlapping spheres). Comparisons between these two methods show very good agreement. The results demonstrate that the radius of gyration is responsible for the amount of <span class="hlt">light</span> <span class="hlt">scattered</span> towards the back direction while the total volume of an aggregate defines the shape of the <span class="hlt">light</span> <span class="hlt">scattering</span> patterns. Small changes of the fractal dimension can be neglected (provided that the fractal prefactor is accordingly modified in a suitable way). The overlap level, if the radius of gyration is kept constant, introduces barely visible changes to the <span class="hlt">light</span> <span class="hlt">scattering</span> diagrams which suggest that a simple aggregate model, composed of particles being in point contact, can be used instead of a structure in early sintering stage when overlap of primary particles is not so high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=surface+AND+tension&pg=3&id=EJ202043','ERIC'); return false;" href="http://eric.ed.gov/?q=surface+AND+tension&pg=3&id=EJ202043"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">Scattering</span> by Surface Tension Waves.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Weisbuch, G.; Garbay, F.</p> <p>1979-01-01</p> <p>This simple and inexpensive experiment is an illustration of the physical concepts of interaction between <span class="hlt">light</span> and surface tension waves, and provides a new method of measuring surface tension. (Author/GA)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10926478','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10926478"><span id="translatedtitle">Structural Interpretations of Static <span class="hlt">Light</span> <span class="hlt">Scattering</span> Patterns of Fractal Aggregates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lambert; Thill; Ginestet; Audic; Bottero</p> <p>2000-08-15</p> <p>A method based on static <span class="hlt">light</span> <span class="hlt">scattering</span> by fractal aggregates is introduced to extract structural information. In this study, we determine the <span class="hlt">scattered</span> intensity by a fractal aggregate calculating the Structure and the Form factors noted, respectively, S(q) and F(q). We use the approximation of the mean field Mie <span class="hlt">scattering</span> by fractal aggregates (R. Botet, P. Rannou, and M. Cabane, appl. opt. 36, 8791, 1997). This approximation is validated by a comparison of the <span class="hlt">scattering</span> and extinction cross sections values calculated using, on the one hand, Mie theory with a mean optical index n) and, on the other hand, the mean field approximation. <span class="hlt">Scattering</span> and extinction cross sections values differ by about 5%. We show that the mean environment of primary <span class="hlt">scatterers</span> characterized by the optical index n(s) must be taken into account to interpret accurately the <span class="hlt">scattering</span> pattern from fractal aggregates. Numerical simulations were done to evaluate the influence of the fractal dimension values (D(f)>2) and of the radius of gyration or the number of primary particles within the aggregates (N=50 to 250) on the <span class="hlt">scatterers</span>' mean optical contrast (n(s)/n). This last parameter plays a major role in determining the Form factor F(q) which corresponds to the primary particles' <span class="hlt">scattering</span>. In associating the mean optical index (n) to structural characteristics, this work provides a theoretical framework to be used to provide additional structural information from the <span class="hlt">scattering</span> pattern of a fractal aggregate (cf. Part II). Copyright 2000 Academic Press.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/245665','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/245665"><span id="translatedtitle">Imaging back <span class="hlt">scattered</span> and near back <span class="hlt">scattered</span> <span class="hlt">light</span> in ignition scale plasmas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kirkwood, R.K.; Back, C.A.; Glenzer, S.H.; Moody, J.D.</p> <p>1996-05-07</p> <p>Diagnostics have been developed and fielded at the Nova laser facility that image <span class="hlt">scattered</span> <span class="hlt">light</span> in the vicinity of the final laser focusing lens. The absolute calibration of optical components exposed to the target debris have been achieved by a combination of routine in situ calibration and maintenance. The <span class="hlt">scattering</span> observed from plasmas relevant to ignition experiments indicates that <span class="hlt">light</span> <span class="hlt">scattered</span> just outside the lens can be larger than that collected by the lens, and is a significant factor in the energy balance when the f number is high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JOSAB..21..214R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JOSAB..21..214R"><span id="translatedtitle">Electrical generation of stationary <span class="hlt">light</span> in random <span class="hlt">scattering</span> media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Redmond, S. M.; Armstrong, G. L.; Chan, H.-Y.; Mattson, E.; Mock, A.; Li, B.; Potts, J. R.; Cui, M.; Rand, S. C.; Oliveira, S. L.; Marchal, J.; Hinklin, T.; Laine, R. M.</p> <p>2004-01-01</p> <p>In recent years there has been great interest in controlling the speed of propagation of electromagnetic waves. In gases and crystals, coherent techniques have been applied to alter the speed of <span class="hlt">light</span> without changing the physical or chemical structure of the medium. Also, <span class="hlt">light</span> transmitted by highly disordered solids has exhibited signatures of Anderson localization, indicating the existence of a regime of ``stopped'' <span class="hlt">light</span> that is mediated by random elastic <span class="hlt">scattering</span>. However, to date, <span class="hlt">light</span> has not been generated in a random medium as a pointlike excitation that is fixed in space from the outset. Here we report experimental evidence for the electrical generation and confinement of <span class="hlt">light</span> within nanosized volumes of a random dielectric <span class="hlt">scattering</span> medium in which a population inversion has been established, and discuss the properties of these novel <span class="hlt">light</span> sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9672E..12L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9672E..12L"><span id="translatedtitle">Cell <span class="hlt">light</span> <span class="hlt">scattering</span> characteristic research based on FDTD algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Xiaogang; Zhu, Hao; Li, Wenchao; Ye, Changbin</p> <p>2015-10-01</p> <p>As with the number of cancer increases year by year, so it is important to be found and treated earlier. With biological cells and tissues are sensitive to infrared and visible <span class="hlt">light</span>, cell morphology and physical structure of the optical properties can easily obtain, we can provide theoretical basis for the early diagnosis of cancer by observing the difference of optical properties between normal and cancerous cells. Compared with Mie <span class="hlt">scattering</span> theory, finite difference time domain (FDTD) algorithm can analyze any complex structure model. In this paper we use mathematical modeling method to establish the single cell mathematical model and with finite difference time domain algorithm to simulate the propagation and <span class="hlt">scattering</span> of <span class="hlt">light</span> in the biological cells, you can calculate the <span class="hlt">scattering</span> of electromagnetic field distribution at anytime and anywhere. With radar cross section (RCS) to measure the results of the <span class="hlt">scattering</span> characteristics. Due to the difference between normal cells and cancerous cells are embodied in cell shape, size and the refractive index, through the simulation we can get different cell parameters of <span class="hlt">light</span> <span class="hlt">scattering</span> information, Find out the cell parameters change the changing rule of the influence on the <span class="hlt">scattering</span> characteristics and find out change regularity of <span class="hlt">scattering</span> characteristics. These data can judge very accurate of the cells is normal or cancerous cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Nanos...714114Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanos...714114Q"><span id="translatedtitle">Hybrid graphene nematic liquid crystal <span class="hlt">light</span> <span class="hlt">scattering</span> device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qasim, M. M.; Khan, A. A.; Kostanyan, A.; Kidambi, P. R.; Cabrero-Vilatela, A.; Braeuninger-Weimer, P.; Gardiner, D. J.; Hofmann, S.; Wilkinson, T. D.</p> <p>2015-08-01</p> <p>A hybrid graphene nematic liquid crystal (LC) <span class="hlt">light</span> <span class="hlt">scattering</span> device is presented. This device exploits the inherent poly-crystallinity of chemical vapour deposited (CVD) graphene films to induce directional anchoring and formation of LC multi-domains. This thereby enables efficient <span class="hlt">light</span> <span class="hlt">scattering</span> without the need for crossed polarisers or separate alignment layers/additives. The hybrid LC device exhibits switching thresholds at very low electric fields (< 1 V μm-1) and repeatable, hysteresis free characteristics. This exploitation of LC alignment effects on CVD graphene films enables a new generation of highly efficient nematic LC <span class="hlt">scattering</span> displays as well as many other possible applications.A hybrid graphene nematic liquid crystal (LC) <span class="hlt">light</span> <span class="hlt">scattering</span> device is presented. This device exploits the inherent poly-crystallinity of chemical vapour deposited (CVD) graphene films to induce directional anchoring and formation of LC multi-domains. This thereby enables efficient <span class="hlt">light</span> <span class="hlt">scattering</span> without the need for crossed polarisers or separate alignment layers/additives. The hybrid LC device exhibits switching thresholds at very low electric fields (< 1 V μm-1) and repeatable, hysteresis free characteristics. This exploitation of LC alignment effects on CVD graphene films enables a new generation of highly efficient nematic LC <span class="hlt">scattering</span> displays as well as many other possible applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04094a</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JChPh.136q5102S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.136q5102S"><span id="translatedtitle">Osmotic virial coefficients for model protein and colloidal solutions: Importance of ensemble constraints in the analysis of <span class="hlt">light</span> <span class="hlt">scattering</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siderius, Daniel W.; Krekelberg, William P.; Roberts, Christopher J.; Shen, Vincent K.</p> <p>2012-05-01</p> <p>Protein-protein interactions in solution may be quantified by the osmotic second virial coefficient (OSVC), which can be measured by various experimental techniques including <span class="hlt">light</span> <span class="hlt">scattering</span>. Analysis of <span class="hlt">Rayleigh</span> <span class="hlt">light</span> <span class="hlt">scattering</span> measurements from such experiments requires identification of a <span class="hlt">scattering</span> volume and the thermodynamic constraints imposed on that volume, i.e., the statistical mechanical ensemble in which <span class="hlt">light</span> <span class="hlt">scattering</span> occurs. Depending on the set of constraints imposed on the <span class="hlt">scattering</span> volume, one can obtain either an apparent OSVC, A2,app, or the true thermodynamic OSVC, {B_{22}^{osm}}, that is rigorously defined in solution theory [M. A. Blanco, E. Sahin, Y. Li, and C. J. Roberts, J. Chem. Phys. 134, 225103 (2011), 10.1063/1.3596726]. However, it is unclear to what extent A2,app and {B_{22}^{osm}} differ, which may have implications on the physical interpretation of OSVC measurements from <span class="hlt">light</span> <span class="hlt">scattering</span> experiments. In this paper, we use the multicomponent hard-sphere model and a well-known equation of state to directly compare A2,app and {B_{22}^{osm}}. Our results from the hard-sphere equation of state indicate that A2,app underestimates {B_{22}^{osm}}, but in a systematic manner that may be explained using fundamental thermodynamic expressions for the two OSVCs. The difference between A2,app and {B_{22}^{osm}} may be quantitatively significant, but may also be obscured in experimental application by statistical uncertainty or non-steric interactions. Consequently, the two OSVCs that arise in the analysis of <span class="hlt">light</span> <span class="hlt">scattering</span> measurements do formally differ, but in a manner that may not be detectable in actual application.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002QuEle..32..945B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002QuEle..32..945B"><span id="translatedtitle">LASER BIOLOGY AND MEDICINE: <span class="hlt">Light</span> <span class="hlt">scattering</span> study of rheumatoid arthritis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beuthan, J.; Netz, U.; Minet, O.; Klose, Annerose D.; Hielscher, A. H.; Scheel, A.; Henniger, J.; Müller, G.</p> <p>2002-11-01</p> <p>The distribution of <span class="hlt">light</span> <span class="hlt">scattered</span> by finger joints is studied in the near-IR region. It is shown that variations in the optical parameters of the tissue (<span class="hlt">scattering</span> coefficient μs, absorption coefficient μa, and anisotropy factor g) depend on the presence of the rheumatoid arthritis (RA). At the first stage, the distribution of <span class="hlt">scattered</span> <span class="hlt">light</span> was measured in diaphanoscopic experiments. The convolution of a Gaussian error function with the <span class="hlt">scattering</span> phase function proved to be a good approximation of the data obtained. Then, a new method was developed for the reconstruction of distribution of optical parameters in the finger cross section. Model tests of the quality of this reconstruction method show good results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950059754&hterms=Reflection+light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DReflection%2Blight','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950059754&hterms=Reflection+light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DReflection%2Blight"><span id="translatedtitle">An experimental study of <span class="hlt">light</span> <span class="hlt">scattering</span> by large, irregular particles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcguire, Audrey F.; Hapke, Bruce W.</p> <p>1995-01-01</p> <p>The intensity and polarization of <span class="hlt">light</span> <span class="hlt">scattered</span> by a variety of types of artificial partices large compared to the wavelength were measured as a function of phase angle. Shape, surface roughness, absorption coefficient, and internal <span class="hlt">scattering</span> coefficient were varied systematically and their effects studied. <span class="hlt">Scattering</span> by clear, smooth-surfaced spheres is in quantitative agreement with the predictions of the geometrical optics (ray theory) approximation to physical optics (Mie theory). The phase functions of almost all of the particles measured have both forward and backward <span class="hlt">scattering</span> lobes. A two-parameter, double Henyey-Greenstein function generally provides reasonably good descriptions of the data, while keeping the number of free parameters to the minimum necessary. On a double Henyey- Greenstein parameter plot all of the particles fall into an L-shaped area of restricted size in which the location is characteristic of the particle type. Formalisms based on the equivalent slab model are also given for estimating the <span class="hlt">scattering</span> efficiency of a large, irregular particle. For most dielectric particles the transmitted, forward <span class="hlt">scattered</span> <span class="hlt">light</span> is partially negatively polarized. It is this component that is respopnsible for the well-known maximum in the polarization curves of planetary regoliths at phase angles around 100 deg. For phase angles between about 30 deg and 70 deg the internally <span class="hlt">scattered</span> <span class="hlt">light</span> is found to be randomly polarized in the particles studied here, so that the only contribution to the second component of the Stokes vector is by Fresnel reflection from the particle surface. If this empirical result is general, measurement of the second Stokes vector of the <span class="hlt">light</span> <span class="hlt">scattered</span> from a regolith at these angles may provide a method of remotely measuring the mean refractive index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20068663','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20068663"><span id="translatedtitle">Radiant intensity of <span class="hlt">light</span> <span class="hlt">scattered</span> from clouds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Plass, G N; Kattawar, G W</p> <p>1968-04-01</p> <p>A Monte Carlo method that accurately allows for the numerous small angle <span class="hlt">scattering</span> events is used to calculate the reflected and transmitted radiance and flux of visible radiation that has interacted with cumulus clouds. The variation of these quantities with solar zenith angle, optical thickness of the cloud, and surface albedo is studied. When the surface albedo is zero, the reflected radiance has a relative maximum at the horizon (except for very thick clouds and incident beam near zenith). When the incident beam is near the horizon, there is a strong maximum in the reflected radiance on the solar horizon and a pronounced minimum near the zenith. There is a relative maximum in the transmitted radiance around the direction of the incident beam until the cloud becomes thick in that direction. In most instances, the variations are greatly decreased when the surface albedo is unity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20134829','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20134829"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> by a spheroidal particle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Asano, S; Yamamoto, G</p> <p>1975-01-01</p> <p>The solution of electromagnetic <span class="hlt">scattering</span> by a homogeneous prolate (or oblate) spheroidal particle with an arbitrary size and refractive index is obtained for any angle of incidence by solving Maxwell's equations under given boundary conditions. The method used is that of separating the vector wave equations in the spheroidal coordinates and expanding them in terms of the spheroidal wavefunctions. The unknown coefficients for the expansion are determined by a system of equations derived from the boundary conditions regarding the continuity of tangential components of the electric and magnetic vectors across the surface of the spheroid. The solutions both in the prolate and oblate spheroidal coordinate systems result in a same form, and the equations for the oblate spheroidal system can be obtained from those for the prolate one by replacing the prolate spheroidal wavefunctions with the oblate ones and vice versa. For an oblique incidence, the polarized incident wave is resolved into two components, the TM mode for which the magnetic vector vibrates perpendicularly to the incident plane and the TE mode for which the electric vector vibrates perpendicularly to this plane. For the incidence along the rotation axis the resultant equations are given in the form similar to the one for a sphere given by the Mie theory. The physical parameters involved are the following five quantities: the size parameter defined by the product of the semifocal distance of the spheroid and the propagation constant of the incident wave, the eccentricity, the refractive index of the spheroid relative to the surrounding medium, the incident angle between the direction of the incident wave and the rotation axis, and the angles that specify the direction of the <span class="hlt">scattered</span> wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..APRG15100T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..APRG15100T"><span id="translatedtitle">Resonant <span class="hlt">Light</span> <span class="hlt">Scattering</span> to Measure BEC-Pairing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timmermans, Eddy; Tommasini, Paolo</p> <p>1997-04-01</p> <p>We present a single-<span class="hlt">scattering</span> formalism for incoherent resonant <span class="hlt">light</span> <span class="hlt">scattering</span> by dilute quantum gas systems such as the atomic-trap Bose-Einstein condensates. We point out that resonant <span class="hlt">scattering</span> gives access to more information than the dynamical structure factor, familiar from non-resonant <span class="hlt">scattering</span>. In particular, we show that the detuning dependence of the incoherent <span class="hlt">scattering</span> cross-section allows the direct determination of the BEC pairing density < ψ ψ >, a broken symmetry which is of fundamental importance in understanding the microscopic structure of the condensate. Furthermore, the technique can be viewed as an experimental test to determine wether or not the condensate is in a good number state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARL47004R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARL47004R"><span id="translatedtitle">Inferring mixture Gibbs free energies from static <span class="hlt">light</span> <span class="hlt">scattering</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ross, David; Wahle, Christopher; Thurston, George</p> <p></p> <p>We describe a <span class="hlt">light</span> <span class="hlt">scattering</span> partial differential equation for the free energy of mixing that applies to connected, isotropic ternary and quaternary liquid composition domains, including restricted domains which may not touch all binary axes. For restricted domains, contrasting <span class="hlt">light</span> <span class="hlt">scattering</span> efficiency patterns obtained at different wavelengths can correspond to the same underlying free energy, and supplement the available information. We discuss well-posed problems for this fully nonlinear, degenerate elliptic partial differential equation. Using Monte Carlo simulations, we provide estimates of the overall system measurement time and sample spacing needed to determine the free energy to a desired degree of accuracy, and indicate how measurement time depends on instrument throughput. These methods provide a way to use static <span class="hlt">light</span> <span class="hlt">scattering</span> to measure, directly, mixing free energies of many systems that contain liquid domains. Supported by NIH EY018249.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.2963..266H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.2963..266H"><span id="translatedtitle">Solar-stimulated inelastic <span class="hlt">light</span> <span class="hlt">scattering</span> in clear seawater</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Chuanmin; Voss, Kenneth J.</p> <p>1997-02-01</p> <p>Solar Fraunhofer lines are used as indicators of the inelastic <span class="hlt">light</span> <span class="hlt">scattering</span> in the sea water. Data from both in-shore and off-shore are presented and compared with results of theoretical modeling. Very good agreement is found between the modeled and measured proportion of inelastic to elastically <span class="hlt">scattered</span> and direct <span class="hlt">light</span> at 589 nm when the Raman <span class="hlt">scattering</span> coefficient of Marshall and Smith is used, as opposed to that of Slusher and Derr. At 656 nm the agreement is not as good, indicating possible interference from other sources such a Chlorophyll fluorescence. Recent work has extended the measurements of include smaller absorption lines, such as 689 nm, where significant filling has been measured at the surface due to the Chlorophyll fluorescence. This technique allows the natural fluorescence to be measured, even at the surface where there is still a significant amount of direct solar <span class="hlt">light</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860063705&hterms=Light+Matter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DLight%2BMatter','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860063705&hterms=Light+Matter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DLight%2BMatter"><span id="translatedtitle"><span class="hlt">Scattered</span> <span class="hlt">light</span> in the IUE spectra of Epsilon Aurigae</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Altner, B.; Chapman, R. D.; Kondo, Y.; Stencel, R. E.</p> <p>1986-01-01</p> <p>Recent infrared photometry indicates that the alleged disk of particulate matter surrounding the mysterious secondary object in the Epsilon Aur system is cold, around 500 K. IUE spectra, on the other hand, contain significant flux in excess of that expected from an F0 Ia star in the far UV, which if interpreted as a hot secondary star leads to a possible contradiction with the IR data. Other models of the UV excess have been proposed, including the idea that the bulk of the short-wavelength flux is <span class="hlt">light</span> <span class="hlt">scattered</span> into the SWP camera from longer wavelengths. With the recent availability of a detailed generalized IUE descattering algorithm it is possible to thoroughly investigate the <span class="hlt">scattered-light</span> contribution to the short-wavelength continuum. It is found that the IUE spectra are indeed partially contaminated by <span class="hlt">scattered</span> <span class="hlt">light</span>, but that even after correction for this instrumental effect a significant time-dependent UV excess is still present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900007781&hterms=colloid&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcolloid','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900007781&hterms=colloid&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcolloid"><span id="translatedtitle">Laser <span class="hlt">light</span> <span class="hlt">scattering</span> as a probe of fractal colloid aggregates</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weitz, David A.; Lin, M. Y.</p> <p>1989-01-01</p> <p>The extensive use of laser <span class="hlt">light</span> <span class="hlt">scattering</span> is reviewed, both static and dynamic, in the study of colloid aggregation. Static <span class="hlt">light</span> <span class="hlt">scattering</span> enables the study of the fractal structure of the aggregates, while dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> enables the study of aggregation kinetics. In addition, both techniques can be combined to demonstrate the universality of the aggregation process. Colloidal aggregates are now well understood and therefore represent an excellent experimental system to use in the study of the physical properties of fractal objects. However, the ultimate size of fractal aggregates is fundamentally limited by gravitational acceleration which will destroy the fractal structure as the size of the aggregates increases. This represents a great opportunity for spaceborne experimentation, where the reduced g will enable the growth of fractal structures of sufficient size for many interesting studies of their physical properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21246923','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21246923"><span id="translatedtitle">Optical model of transient <span class="hlt">light</span> <span class="hlt">scattering</span> in ferroelectric liquid crystals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Loiko, V. A. Konkolovich, A. V.; Miskevich, A. A.</p> <p>2009-03-15</p> <p>A static optical model is developed for the effect of field-induced transient <span class="hlt">scattering</span> on coherent <span class="hlt">light</span> transmission through ferroelectric liquid crystals. <span class="hlt">Scattering</span> processes are described by introducing an optically anisotropic medium containing <span class="hlt">scatterers</span> (transient domains). The results presented in the paper are obtained for a plane parallel layer of ferroelectric liquid crystals with a planar helicoidal structure under normal illumination with a linearly polarized plane wave. An analysis is presented of the coherent transmittance of the layer in static applied electric fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985SPIE..540..643H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985SPIE..540..643H"><span id="translatedtitle">Banquet Speech Some Sketches Of <span class="hlt">Rayleigh</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howard, John N.</p> <p>1985-11-01</p> <p>Several short sketches are presented of Lord <span class="hlt">Rayleigh</span>, to show his method of working and his interaction with his fellow scientists. The topics discussed are: his research on the blue of the sky (<span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>); his rescue of Waterston from near-oblivion; his research on surface acoustic waves (<span class="hlt">Rayleigh</span> waves); his collaboration with Agnes Pockels; his research on blackbody radiation (the <span class="hlt">Rayleigh</span>-Jeans Law).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1065569','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1065569"><span id="translatedtitle">Neutron and <span class="hlt">light</span> <span class="hlt">scattering</span> studies of <span class="hlt">light</span>-harvesting photosynthetic antenna complexes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tang, Kuo-Hsiang; Blankenship, Robert E.</p> <p>2011-06-28</p> <p>Small-angle neutron <span class="hlt">scattering</span> (SANS) and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS) have been employed in studying the structural information of various biological systems, particularly in systems without high-resolution structural information available. In this report, we briefly present some principles and biological applications of neutron <span class="hlt">scattering</span> and DLS, compare the differences in information that can be obtained with small-angle X-ray <span class="hlt">scattering</span> (SAXS), and then report recent studies of SANS and DLS, together with other biophysical approaches, for <span class="hlt">light</span>-harvesting antenna complexes and reaction centers of purple and green phototrophic bacteria.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20068605','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20068605"><span id="translatedtitle"><span class="hlt">Scattering</span> of coherent and incoherent <span class="hlt">light</span> by latex hydrosols.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sherman, G C; Harris, F S; Morse, F L</p> <p>1968-03-01</p> <p>Experimental study of the <span class="hlt">scattering</span> of coherent and incoherent <span class="hlt">light</span> by latex hydrosols has been extended to determine the effects of larger diameter <span class="hlt">scatterers</span> and of several <span class="hlt">scatterer</span> concentrations. The angular dependence of the intensity of the <span class="hlt">light</span> <span class="hlt">scattered</span> by latex spheres suspended in water was measured. Two <span class="hlt">light</span> sources were used: (1) a continuous wave He-Ne laser radiating at 6328 A and (2) a high pressure, xenon arc lamp limited to a 100-micro bandwidth centered at 6328 A. The number of particles in the <span class="hlt">scattering</span> volume coherently illuminated with the laser was greater than the number coherently illuminated with the xenon lamp by a factor > 5 x 10(5). Six hydrosols were studied: three suspensions of particles polydispersed in size (diameter ranges from 6 micro to 14 micro, 12 micro to 35 micro, and 25 micro to 55 micro) and three suspensions of particles monodispersed in size (0.796-micro diam and concentration ranging from 5.7 x 10(7) particles/cm(3) to 5.7 x 10(5) particles/cm(3)). For these six suspensions, the data from the two <span class="hlt">light</span> sources agree to within the possible experimental error of 20%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........39H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........39H"><span id="translatedtitle">Novel Trapping and <span class="hlt">Scattering</span> of <span class="hlt">Light</span> in Resonant Nanophotonic Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, Chia Wei</p> <p></p> <p>Nanophotonic structures provide unique ways to control <span class="hlt">light</span> and alter its behaviors in ways not possible in macroscopic structures. In this thesis, we explore novel behaviors of <span class="hlt">light</span> created by nanophotonic structures, with a common theme on resonance effects. The first half of the thesis focuses on a peculiar type of electromagnetic resonance, where the resonance lifetime diverges to infinity. These states, called bound states in the continuum, remain localized in space even though their frequency lie within a continuum of extended modes. We find such states in photonic crystal slabs and the surface of bulk photonic crystals. We show the conditions necessary for them to exist, and provide the first experimental observation of these unusual states. We also show that these states have a topological nature, with conserved and quantized topological charges that govern their generation, evolution, and annihilation. The second half of the thesis concerns <span class="hlt">light</span> <span class="hlt">scattering</span> from resonant nanophotonic structures, where resonances can enhance or suppress <span class="hlt">scattering</span> at particular wavelengths and angles. We show that multiple resonances in one nanostructure and in the same multipole channel generally lead to a <span class="hlt">scattering</span> dark state where the structure becomes transparent. Based on the coherent interference from multiple <span class="hlt">scatterers</span>, we show there are geometries that can achieve a sharp structural color where the hue, saturation, and brightness are all viewing-angle independent. We also invent a new type of transparent display based on wavelength-selective <span class="hlt">light</span> <span class="hlt">scattering</span> from nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20111159','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20111159"><span id="translatedtitle"><span class="hlt">Scattered</span> and reflected <span class="hlt">light</span> intensities above the atmosphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thompson, B C; Wells, M B</p> <p>1971-07-01</p> <p>A calculational method is described that was developed for use in predicting the angular distribution of the upwelling flux of sunlight <span class="hlt">scattered</span> by the atmosphere and reflected by the ground. Monte Carlo calculations of the radiation escaping the top of a plane-parallel model atmosphere were used as input in a computer procedure that integrates the reflected intensities over the sunlit portion of the top of the earth's atmosphere, which is visible by a receiver located on a spacecraft. Calculations were performed for a model maritime atmosphere, with and without low-altitude cloud layer, and a model continental atmosphere, which includes treatment of the effects of aerosol, <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>, and ozone absorption. The ground surface was assumed to be a Lambert reflector. The results of the Monte Carlo calculation for five wavelengths between 370 nm and 780 nm were compared with measured data from the Ames Research Center earth albedo experiment on the OSO-3 satellite. Agreement between calculated and measured values was sufficiently good to warrant the conclusion that reasonable estimates of the angular distribution of the radiation reaching a near-earth spacecraft from different atmospheric conditions could be calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19138548','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19138548"><span id="translatedtitle">Optical cavitation probe using <span class="hlt">light</span> <span class="hlt">scattering</span> from bubble clouds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iida, Yasuo; Lee, Judy; Kozuka, Teruyuki; Yasui, Kyuichi; Towata, Atsuya; Tuziuti, Toru</p> <p>2009-04-01</p> <p>To understand the behaviour of systems containing clouds of bubbles (multibubble system) in real sonochemical reactors, a new diagnosis method, i.e., optical cavitation probe (OCP), has been proposed. When a laser beam is introduced into the cavitation bubble cloud, the <span class="hlt">scattered</span> <span class="hlt">light</span> intensity changes by the collective oscillation of cavitation bubbles. The frequency domain spectrum of the <span class="hlt">scattered</span> <span class="hlt">light</span> contains rich information on the cavitation bubble clouds, comparable with the acoustic emission spectra detected by a hydrophone. The significant merits of OCP, such as capability for spatially resolved, non-invasive measurement of the cavitation bubble clouds, robustness even in a violent cavitation field have been experimentally demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20490204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20490204"><span id="translatedtitle">Symmetry theorems on the forward and backward <span class="hlt">scattering</span> Mueller matrices for <span class="hlt">light</span> <span class="hlt">scattering</span> from a nonspherical dielectric <span class="hlt">scatterer</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, C R; Kattawar, G W; Parkin, M E; Herb, P</p> <p>1987-10-01</p> <p>The symmetry theorems on the complete forward and backward <span class="hlt">scattering</span> Mueller matrices for <span class="hlt">light</span> <span class="hlt">scattering</span> from a single dielectric <span class="hlt">scatterer</span> (as opposed to an ensemble of <span class="hlt">scatterers</span>) are systematically and thoroughly analyzed. Symmetry operations considered include discrete rotations about the incident direction and mirror planes not coinciding with the <span class="hlt">scattering</span> plane. For forward <span class="hlt">scattering</span> we find sixteen different symmetry shapes (not including the totally asymmetric one), which may be classified into five symmetry classes, with identical reductions in the forward <span class="hlt">scattering</span> matrices for all symmetry shapes that fall into the same symmetry class. For backward <span class="hlt">scattering</span> we find only four different symmetry shapes, which may be classified into only two symmetry classes. The forward <span class="hlt">scattering</span> symmetry theorems also lead to a symmetry theorem on the total extinction cross section. Based on the conclusions of this work it should be possible to design quick and nondestructive methods for the identification of certain small objects, when suitable partial information about the objects to be identified is already available. A promising practical example is given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27519113','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27519113"><span id="translatedtitle">Coherent anti-Stokes Raman <span class="hlt">scattering</span> imaging under ambient <span class="hlt">light</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Yinxin; Liao, Chien-Sheng; Hong, Weili; Huang, Kai-Chih; Yang, Huaidong; Jin, Guofan; Cheng, Ji-Xin</p> <p>2016-08-15</p> <p>We demonstrate an ambient <span class="hlt">light</span> coherent anti-Stokes Raman <span class="hlt">scattering</span> microscope that allows CARS imaging to be operated under environmental <span class="hlt">light</span> for field use. The CARS signal is modulated at megahertz frequency and detected by a photodiode equipped with a lab-built resonant amplifier, then extracted through a lock-in amplifier. The filters in both the spectral domain and the frequency domain effectively blocked the room <span class="hlt">light</span> contamination of the CARS image. In situ hyperspectral CARS imaging of tumor tissue under ambient <span class="hlt">light</span> is demonstrated. PMID:27519113</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740012203','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740012203"><span id="translatedtitle">Study of resonance <span class="hlt">light</span> <span class="hlt">scattering</span> for remote optical probing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Penney, C. M.; Morey, W. W.; St. Peters, R. L.; Silverstein, S. D.; Lapp, M.; White, D. R.</p> <p>1973-01-01</p> <p>Enhanced <span class="hlt">scattering</span> and fluorescence processes in the visible and UV were investigated which will enable improved remote measurements of gas properties. The theoretical relationship between <span class="hlt">scattering</span> and fluorescence from an isolated molecule in the approach to resonance is examined through analysis of the time dependence of re-emitted <span class="hlt">light</span> following excitation of pulsed incident <span class="hlt">light</span>. Quantitative estimates are developed for the relative and absolute intensities of fluorescence and resonance <span class="hlt">scattering</span>. New results are obtained for depolarization of <span class="hlt">scattering</span> excited by <span class="hlt">light</span> at wavelengths within a dissociative continuum. The experimental work was performed in two separate facilities. One of these utilizes argon and krypton lasers, single moded by a tilted etalon, and a 3/4 meter double monochromator. This facility was used to determine properties of the re-emission from NO2, I2 and O3 excited by visible <span class="hlt">light</span>. The second facility involves a narrow-line dye laser, and a 3/4 meter single monochromator. The dye laser produces pulsed <span class="hlt">light</span> with 5 nsec pulse duration and 0.005 nm spectral width.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1542P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1542P"><span id="translatedtitle">Investigation of <span class="hlt">light</span> <span class="hlt">scattering</span> on a single dust grain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlu, Jiri; Nemecek, Zdenek; Safrankova, Jana; Barton, Petr</p> <p>2016-07-01</p> <p>Complex phenomenon of <span class="hlt">light</span> <span class="hlt">scattering</span> by dust grains plays an important role in all dust--<span class="hlt">light</span> interactions, especially in space, e.g., <span class="hlt">light</span> passing through dense dusty clouds in the space as well as in the upper atmosphere, dust charging by photoemission, etc. When the wavelength of the incident <span class="hlt">light</span> is about the size of the grain, the Mie theory is often used to characterize the <span class="hlt">scattering</span> process. Unfortunately, we have only very limited knowledge of necessary material constants for most of the space-related materials and also the solution of Mie equations for general grain shapes is difficult or unknown. We develop an apparatus for observations of <span class="hlt">light</span> <span class="hlt">scattering</span> on small (micrometer-sized) arbitrary shaped dust grains. We directly measure the <span class="hlt">scattering</span> by levitating grains in the field created by the standing-wave ultrasonic trap, where we can study single grains or small grain clusters. The experiment is performed at atmospheric air --- unlike other experiments, where grains were measured in water or other liquids. Therefore, the background effects are significantly reduced. Currently, the trap is under development and first tests are carried out. Besides initial results, we focus on theoretical computations of the ultrasonic field of the selected trap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992SPIE.1727..341P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992SPIE.1727..341P&link_type=ABSTRACT"><span id="translatedtitle">Bulk and surface <span class="hlt">light</span> <span class="hlt">scattering</span> from transparent silica aerogel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Platzer, Werner J.; Bergkvist, Mikael</p> <p>1992-11-01</p> <p>Elastic <span class="hlt">light</span> <span class="hlt">scattering</span> has been used to study structural properties of different transparent aerogels, which may be used as filling materials in super-windows. With a goniometer having an angular resolution better than 0.6 degree(s) and a He-Ne laser as the <span class="hlt">light</span> source we investigated the angular distribution of <span class="hlt">scattered</span> intensity from transparent silica aerogels and one xerogel. The densities ranged between 0.11 and 0.60 gcm-3. An exponential correlation function for the density fluctuations of a random porous medium has been utilized to analyze the large-angle <span class="hlt">scattering</span>, which is dominated by bulk <span class="hlt">scattering</span>, for different polarization of the incident <span class="hlt">light</span>. The determination of correlation lengths in the nanometer range was possible, because the absolute <span class="hlt">scattering</span> intensities were determined. For relative angular dependence measurements, this range would have been accessible only to small angle x-ray <span class="hlt">scattering</span> (SAXS). The resulting mean pore sizes between 8 nm and 50 nm and specific surface areas between 500 and 700 m2/g agree well with nitrogen-porosimetry data from the literature. The data compare quite well with correlation lengths calculated from specular transmittance data from an ordinary spectrophotometer. This method, which is not sensitive to the angular distribution of superposed forward <span class="hlt">scattering</span> with large correlation lengths, has also been applied to a series of base-catalyzed TMOS aerogels with different catalyst concentrations. The forward <span class="hlt">scattering</span> peak of the signal may be attributed to correlation lengths in the micrometer range. Experimental results for aerogel surfaces with evaporated aluminum indicate that this might be due to the surface properties. A quantitative analysis, however, is not possible yet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22565754','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22565754"><span id="translatedtitle">Satellite peaks in the <span class="hlt">scattering</span> of <span class="hlt">light</span> from the two-dimensional randomly rough surface of a dielectric film on a planar metal surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nordam, T; Letnes, P A; Simonsen, I; Maradudin, A A</p> <p>2012-05-01</p> <p>A nonperturbative, purely numerical, solution of the reduced <span class="hlt">Rayleigh</span> equation for the <span class="hlt">scattering</span> of p- and s-polarized <span class="hlt">light</span> from a dielectric film with a two-dimensional randomly rough surface deposited on a planar metallic substrate, has been carried out. It is found that satellite peaks are present in the angular dependence of the elements of the mean differential reflection coefficient in addition to an enhanced backscattering peak. This result resolves a conflict between the results of earlier approximate theoretical studies of <span class="hlt">scattering</span> from this system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26210115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26210115"><span id="translatedtitle">Towards determination of absolute molar mass of cellulose polymer by size exclusion chromatography with mulitple angle laser <span class="hlt">light</span> <span class="hlt">scattering</span> detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pawcenis, Dominika; Thomas, Jacob L; Łojewski, Tomasz; Milczarek, Jakub M; Łojewska, Joanna</p> <p>2015-08-28</p> <p>The study focuses on determination of a set of crucial parameters for molar mass calculation of cellulose from the results of size exclusion chromatography coupled with multiple angle laser <span class="hlt">light</span> <span class="hlt">scattering</span> (MALLS) and differential refractive index (DRI) detectors. In the present work, cellulose has been derivatised to obtain cellulose tricarbanilate (CTC) soluble in tetrahydrofuran (THF). The parameters of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> in the MALLS detector: refractive index increment (dn/dc) and second virial coefficient (A2) of CTC in THF were determined for laser wavelength 658nm. In order to avoid errors resulting from cellulose derivatisation by-products present in the CTC solution, the so called "on-line" method of measuring dn/dc and A2 was applied. Based on the A2 determination, its influence on cellulose molar mass calculations and cellulose molecular dimensions were critically assessed. The latter includes evaluation of artificially aged cellulose towards conceivable branching by conformation plot analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26210115','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26210115"><span id="translatedtitle">Towards determination of absolute molar mass of cellulose polymer by size exclusion chromatography with mulitple angle laser <span class="hlt">light</span> <span class="hlt">scattering</span> detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pawcenis, Dominika; Thomas, Jacob L; Łojewski, Tomasz; Milczarek, Jakub M; Łojewska, Joanna</p> <p>2015-08-28</p> <p>The study focuses on determination of a set of crucial parameters for molar mass calculation of cellulose from the results of size exclusion chromatography coupled with multiple angle laser <span class="hlt">light</span> <span class="hlt">scattering</span> (MALLS) and differential refractive index (DRI) detectors. In the present work, cellulose has been derivatised to obtain cellulose tricarbanilate (CTC) soluble in tetrahydrofuran (THF). The parameters of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> in the MALLS detector: refractive index increment (dn/dc) and second virial coefficient (A2) of CTC in THF were determined for laser wavelength 658nm. In order to avoid errors resulting from cellulose derivatisation by-products present in the CTC solution, the so called "on-line" method of measuring dn/dc and A2 was applied. Based on the A2 determination, its influence on cellulose molar mass calculations and cellulose molecular dimensions were critically assessed. The latter includes evaluation of artificially aged cellulose towards conceivable branching by conformation plot analysis. PMID:26210115</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27296253','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27296253"><span id="translatedtitle">Visualizing <span class="hlt">Light</span> <span class="hlt">Scattering</span> in Silicon Waveguides with Black Phosphorus Photodetectors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Tianjiao; Hu, Shuren; Chamlagain, Bhim; Hong, Tu; Zhou, Zhixian; Weiss, Sharon M; Xu, Ya-Qiong</p> <p>2016-09-01</p> <p>A black phosphorus photodetector is utilized to investigate the <span class="hlt">light-scattering</span> patterns of a silicon waveguide through wavelength- and polarization-dependent scanning photocurrent measurements. The photocurrent signals exhibit similar patterns to the <span class="hlt">light</span>-intensity distribution of the waveguide calculated by finite-difference time-domain simulations, suggesting that photoexcited electron-hole pairs in the silicon waveguide can be injected into phosphorene to induce its photoresponse. PMID:27296253</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27296253','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27296253"><span id="translatedtitle">Visualizing <span class="hlt">Light</span> <span class="hlt">Scattering</span> in Silicon Waveguides with Black Phosphorus Photodetectors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Tianjiao; Hu, Shuren; Chamlagain, Bhim; Hong, Tu; Zhou, Zhixian; Weiss, Sharon M; Xu, Ya-Qiong</p> <p>2016-09-01</p> <p>A black phosphorus photodetector is utilized to investigate the <span class="hlt">light-scattering</span> patterns of a silicon waveguide through wavelength- and polarization-dependent scanning photocurrent measurements. The photocurrent signals exhibit similar patterns to the <span class="hlt">light</span>-intensity distribution of the waveguide calculated by finite-difference time-domain simulations, suggesting that photoexcited electron-hole pairs in the silicon waveguide can be injected into phosphorene to induce its photoresponse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JBO....17h5002M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JBO....17h5002M"><span id="translatedtitle">Effects of acetic acid on <span class="hlt">light</span> <span class="hlt">scattering</span> from cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marina, Oana C.; Sanders, Claire K.; Mourant, Judith R.</p> <p>2012-08-01</p> <p>Acetic acid has been used for decades as an aid for the detection of precancerous cervical lesions, and the use of acetic acid is being investigated in several other tissues. Nonetheless, the mechanism of acetowhitening is unclear. This work tests some of the hypotheses in the literature and measures changes in <span class="hlt">light</span> <span class="hlt">scattering</span> specific to the nucleus and the cytoplasm. Wide angle side <span class="hlt">scattering</span> from both the nucleus and the cytoplasm increases with acetic application to tumorigenic cells, with the increase in nuclear <span class="hlt">scattering</span> being greater. In one cell line, the changes in nuclear <span class="hlt">scattering</span> are likely due to an increase in number or <span class="hlt">scattering</span> efficiency of <span class="hlt">scattering</span> centers smaller than the wavelength of excitation <span class="hlt">light</span>. There are likely several cellular changes that cause acetowhitening and the cellular changes may differ with cell type. These results should lead to a better understanding of acetowhitening and potentially the development of adjunct techniques to improve the utility of acetic acid application. For the well-studied case of cervical tissue, acetowhitening has been shown to be sensitive, but not specific for oncogenic changes needing treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20119195','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20119195"><span id="translatedtitle">Laboratory measurements of <span class="hlt">light</span> <span class="hlt">scattering</span> by simulated atmospheric aerosols.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Quiney, R G; Carswell, A I</p> <p>1972-07-01</p> <p>Using the Stokes vector formulation measurements are reported of the four principal components of the <span class="hlt">scattering</span> matrix under controlled laboratory conditions. Two ranges of <span class="hlt">scattering</span> conditions are considered: atmospheric air as a function of relative humidity (HAZE) and water droplet clouds (FOGS). A 50-mW (63284-A) He-Ne laser is used as the <span class="hlt">light</span> source. A sensitive automated polar nephelometer, which has been developed for these measurements, records the <span class="hlt">scattered</span> <span class="hlt">light</span> as a function of <span class="hlt">scattering</span> angle from 6 degrees to 174 degrees . A digital computer is used to calculate the matrix elements from the raw experimental data. The results may be compared with the theoretical computations of Deirmendjian and the field work of Rozenberg. The results of the experiments show pronounced dependence upon the relative humidity and the properties of the fogs that are explicable qualitatively. However, quantitative inversion of <span class="hlt">light</span> <span class="hlt">scattering</span> data to obtain such information as the size distribution requires comprehensive experiments of high precision and large amounts of computer time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25794718','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25794718"><span id="translatedtitle">Highly sensitive and selective determination of fluorine ion by graphene oxide/nanogold resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>-energy transfer analytical platform.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liang, Aihui; Peng, Jing; Liu, Qingye; Wen, Guiqing; Lu, Zhujun; Jiang, Zhiliang</p> <p>2015-08-15</p> <p>In pH 4.0 acetate buffer solution, fluorine ions react with fluorine reagent (FR) and La(III) to generate blue ternary complex that exhibited strong absorption at about 370 nm. Upon addition of graphene oxide/nanogold (GO/NG) as resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) spectral probe with strong RRS peak at 370 nm, the color changed to gray, and the RRS intensity decreased with the increase of fluorine ion concentration due to the RRS energy transfer (RRSET) from GO/NG to the complex. Under the selected condition, the decreased RRS peak ΔI370 nm was linear to fluorine ion concentration in the range of 6.0 × 10(-8)-1.3 × 10(-5)mol/L, with a detection limit of 3.0 × 10(-8)mol/L F(-). This RRSET method was applied to the analysis of fluorine in toothpaste and water samples, with satisfactory results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24124025','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24124025"><span id="translatedtitle">A simple and sensitive resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> method for determination of As(III) using aptamer-modified nanogold as a probe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tang, Meiling; Wen, Guiqing; Liang, Aihui; Jiang, Zhiliang</p> <p>2014-09-01</p> <p>A simple and selective aptamer (ssDNA)-modified nanogold probe (AussDNA) was prepared for the determination of trace As(III) in HEPES buffer solution (pH 8.2) containing 0.05 mol/L NaCl. The method coupled the aptamer reaction of AussDNA-As(III) and the resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) of nanogold aggregations at 278 nm. When the As(III) concentration increased, the RRS intensity at 278 nm increased to form more nanogold aggregation and a stable As(III)-ssDNA complex. Under selected conditions, the increased RRS intensity (ΔI) was linear to the concentration of As(III) in the range 3.8-230.4 ng/mL, with a detection limit of 1.9 ng/mL. This RRS method was applied to detect As(III) in water samples, with simplicity, sensitivity and selectivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24769380','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24769380"><span id="translatedtitle">Incorporation of flow injection analysis with dual-wavelength overlapping resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> for rapid determination of malachite green and its metabolite in fish.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Jinghui; Qin, Mingyou; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Hu, Xiaoli</p> <p>2014-09-15</p> <p>A flow injection analysis (FIA) system combined with dual-wavelength overlapping resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (DWO-RRS) has been established and validated for rapid determination of malachite green (MG) and its metabolite in fish samples. Under experimental condition, MG would react with Erythrosin (Ery) to form ion-association complexes, resulting in the occurrence of two RRS peaks and a dramatic enhancement of RRS intensity. The maximum RRS peaks were located at 286 nm and 337 nm. It is noted that the increments of both of these two peaks were proportional to the concentration of MG. The detection limit of DWO-RRS was 1.5 ng/mL, which was comparable to several reported methods. Moreover, the results of real sample analysis exhibited an acceptable recovery between 97.5% and 103.6%, indicating that the method had good reproducibility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AcSpA.130...90Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AcSpA.130...90Z"><span id="translatedtitle">Incorporation of flow injection analysis with dual-wavelength overlapping resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> for rapid determination of malachite green and its metabolite in fish</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Jinghui; Qin, Mingyou; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Hu, Xiaoli</p> <p>2014-09-01</p> <p>A flow injection analysis (FIA) system combined with dual-wavelength overlapping resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (DWO-RRS) has been established and validated for rapid determination of malachite green (MG) and its metabolite in fish samples. Under experimental condition, MG would react with Erythrosin (Ery) to form ion-association complexes, resulting in the occurrence of two RRS peaks and a dramatic enhancement of RRS intensity. The maximum RRS peaks were located at 286 nm and 337 nm. It is noted that the increments of both of these two peaks were proportional to the concentration of MG. The detection limit of DWO-RRS was 1.5 ng/mL, which was comparable to several reported methods. Moreover, the results of real sample analysis exhibited an acceptable recovery between 97.5% and 103.6%, indicating that the method had good reproducibility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JAP....88..161J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JAP....88..161J"><span id="translatedtitle">Electrically controlled <span class="hlt">light</span> <span class="hlt">scattering</span> from thermoreversible liquid-crystal gels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janssen, Rob H. C.; Stümpflen, Volker; Broer, Dirk J.; Bastiaansen, Cees W. M.; Tervoort, Theo A.; Smith, Paul</p> <p>2000-07-01</p> <p>Thermoreversible gels of the liquid-crystal LC-E7 with 1,3:2,4-Di-O-benzylidene-D-sorbitol (DBS) form white <span class="hlt">light-scattering</span> films that are reversibly switchable to a clear state by ac electric fields. The <span class="hlt">light</span> <span class="hlt">scattering</span> by the gelled films is an intrinsic material property that originates in the phase diagram of the system displaying a monotectic-type equilibrium ("mesotectic") among a liquid, a solid, and a mesophase at extremely low concentrations of DBS. Electro-optical characteristics and demonstrated viscoelastic behavior of the films produced indicate the applicability of DBS/LC-E7 in large area <span class="hlt">scattering</span>-based flat panel displays and projection systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16523791','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16523791"><span id="translatedtitle">Debye series for <span class="hlt">light</span> <span class="hlt">scattering</span> by a multilayered sphere.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Renxian; Han, Xiange; Jiang, Huifen; Ren, Kuan Fang</p> <p>2006-02-20</p> <p>We have derived the formula for the Debye-series decomposition for <span class="hlt">light</span> <span class="hlt">scattering</span> by a multilayered sphere. This formulism permits the mechanism of <span class="hlt">light</span> <span class="hlt">scattering</span> to be studied. An efficient algorithm is introduced that permits stable calculation for a large sphere with many layers. The formation of triple first-order rainbows by a three-layered sphere and single-order rainbows and the interference of different-order rainbows by a sphere with a gradient refractive index, are then studied by use of the Debye model and Mie calculation. The possibility of taking only one single mode or several modes for each layer is shown to be useful in the study of the <span class="hlt">scattering</span> characteristics of a multilayered sphere and in the measurement of the sizes and refractive indices of particles. PMID:16523791</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20068603','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20068603"><span id="translatedtitle">Monte carlo calculations of <span class="hlt">light</span> <span class="hlt">scattering</span> from clouds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Plass, G N; Kattawar, G W</p> <p>1968-03-01</p> <p>The <span class="hlt">scattering</span> of visible <span class="hlt">light</span> by clouds is calculated from an efficient Monte Carlo code which follows the multiple <span class="hlt">scattered</span> path of the photon. The single <span class="hlt">scattering</span> function is obtained from the Mie theory by integration over a particle size distribution appropriate for cumulus clouds at 0.7-micro wavelength. The photons are followed through a sufficient number of collisions and reflections from the lower surface (which may have any desired albedo) until they make a negligible contribution to the intensity. Various variance reduction techniques are used to improve the statistics. The cloud albedo and the mean optical path of the transmitted and reflected photons are given as a function of the solar zenith angle, optical thickness, and surface albedo. The numerous small angle <span class="hlt">scatterings</span> of the photon in the direction of the incident beam are followed accurately and produce a greater penetration into the cloud than is obtained with a more isotropic and less realistic phase function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20220884','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20220884"><span id="translatedtitle">Optical caustics observed in <span class="hlt">light</span> <span class="hlt">scattered</span> by an oblate spheroid.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lock, James A; Xu, Feng</p> <p>2010-03-10</p> <p>The electromagnetic fields <span class="hlt">scattered</span> when a plane wave is incident on an oblate spheroid in the side-on orientation may be calculated using a generalization of Mie theory, and the results may be decomposed in a Debye series expansion. A number of optical caustics are observed in the computed <span class="hlt">scattered</span> intensity for the one internal reflection portion of the Debye series for <span class="hlt">scattering</span> angles in the vicinity of the first-order rainbow, and are analyzed in terms of the rainbow, transverse cusp, and hyperbolic umbilic caustics of catastrophe optics. The specific features of these three caustics are described, as is their assembly into the global structure of the observed caustics for spheroid <span class="hlt">scattering</span>. It is found that, for a spheroid whose radius is an order of magnitude larger than the wavelength of the incident <span class="hlt">light</span>, the interference structure accompanying the transverse cusp and hyperbolic umbilic caustics is only partially formed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=polystyrene&pg=3&id=EJ301963','ERIC'); return false;" href="http://eric.ed.gov/?q=polystyrene&pg=3&id=EJ301963"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">Scattering</span> by Polymers: Two Experiments for Advanced Undergraduates.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Matthews, G. P.</p> <p>1984-01-01</p> <p>Background information, procedures, equipment, and results for two experiments are presented. The first involves the measurement of the mass-average and degree of coiling of polystyrene and is interpreted by the full mathematical theory of <span class="hlt">light</span> <span class="hlt">scattering</span>. The second is the study of transitions in gelatin. (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=brownian&pg=3&id=EJ021940','ERIC'); return false;" href="http://eric.ed.gov/?q=brownian&pg=3&id=EJ021940"><span id="translatedtitle">A Study of Brownian Motion Using <span class="hlt">Light</span> <span class="hlt">Scattering</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Clark, Noel A.; And Others</p> <p>1970-01-01</p> <p>Presents an advanced laboratory experiment and lecture demonstration by which the intensity spectrum of <span class="hlt">light</span> <span class="hlt">scattered</span> by a suspension of particles in a fluid can be studied. From this spectrum, it is possible to obtain quantitative information about the motion of the particles, including an accurate determination of their diffusion constant.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3146764','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3146764"><span id="translatedtitle">Optical Characterization of Optofluidic Waveguides Using <span class="hlt">Scattered</span> <span class="hlt">Light</span> Imaging</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jenkins, Micah H.; Phillips, Brian S.; Zhao, Yue; Holmes, Matthew R.; Schmidt, Holger; Hawkins, Aaron R.</p> <p>2011-01-01</p> <p>The use of <span class="hlt">scattered</span> <span class="hlt">light</span> images is shown to be an attractive method for the characterization of optofluidic waveguides. The method is shown to be capable of measuring waveguide propagation losses and transmissions between solid and liquid-core structures. Measurement uncertainties are considered and characterized and were typically less than 15%. PMID:21811344</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21811344','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21811344"><span id="translatedtitle">Optical Characterization of Optofluidic Waveguides Using <span class="hlt">Scattered</span> <span class="hlt">Light</span> Imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jenkins, Micah H; Phillips, Brian S; Zhao, Yue; Holmes, Matthew R; Schmidt, Holger; Hawkins, Aaron R</p> <p>2011-08-01</p> <p>The use of <span class="hlt">scattered</span> <span class="hlt">light</span> images is shown to be an attractive method for the characterization of optofluidic waveguides. The method is shown to be capable of measuring waveguide propagation losses and transmissions between solid and liquid-core structures. Measurement uncertainties are considered and characterized and were typically less than 15%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.446.2428S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.446.2428S"><span id="translatedtitle">HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sing, D. K.; Wakeford, H. R.; Showman, A. P.; Nikolov, N.; Fortney, J. J.; Burrows, A. S.; Ballester, G. E.; Deming, D.; Aigrain, S.; Désert, J.-M.; Gibson, N. P.; Henry, G. W.; Knutson, H.; Lecavelier des Etangs, A.; Pont, F.; Vidal-Madjar, A.; Williamson, M. W.; Wilson, P. A.</p> <p>2015-01-01</p> <p>We present Hubble Space Telescope optical and near-IR transmission spectra of the transiting hot-Jupiter WASP-31b. The spectrum covers 0.3-1.7 μm at a resolution R ˜ 70, which we combine with Spitzer photometry to cover the full-optical to IR. The spectrum is dominated by a cloud deck with a flat transmission spectrum which is apparent at wavelengths > 0.52 μm. The cloud deck is present at high altitudes and low pressures, as it covers the majority of the expected optical Na line and near-IR H2O features. While Na I absorption is not clearly identified, the resulting spectrum does show a very strong potassium feature detected at the 4.2σ confidence level. Broadened alkali wings are not detected, indicating pressures below ˜10 mbar. The lack of Na and strong K is the first indication of a sub-solar Na/K abundance ratio in a planetary atmosphere (ln[Na/K] = -3.3 ± 2.8), which could potentially be explained by Na condensation on the planet's night side, or primordial abundance variations. A strong <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> signature is detected at short wavelengths, with a 4σ significant slope. Two distinct aerosol size populations can explain the spectra, with a smaller sub-micron size grain population reaching high altitudes producing a blue <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> signature on top of a larger, lower lying population responsible for the flat cloud deck at longer wavelengths. We estimate that the atmospheric circulation is sufficiently strong to mix micron size particles upwards to the required 1-10 mbar pressures, necessary to explain the cloud deck. These results further confirm the importance of clouds in hot Jupiters, which can potentially dominate the overall spectra and may alter the abundances of key gaseous species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7137P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7137P"><span id="translatedtitle">Tomographic retrieval for <span class="hlt">scattered</span> <span class="hlt">light</span> limb measurements: multiple spectral fit windows to improve the spatial resolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pukite, Janis; Dörner, Steffen; Wagner, Thomas</p> <p>2015-04-01</p> <p>The Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on the ENVISAT satellite probed the atmosphere at the day side of Earth in alternating sequences of nadir and limb measurements from August 2002 to April 2012. Limb measurements allow the retrieval of stratospheric profiles of various trace gases on a global scale. It has been shown that combining measurements of the same air volume from different viewing positions along the orbit, 2D distribution fields of stratospheric trace gases can be acquired in one inversion step. Since the atmospheric <span class="hlt">scattering</span> and absorption processes are wavelength dependent, the spatial sensitivity for limb observations also varies with wavelength. In general, for longer wavelengths, photons from more remote areas along the line of sight are contributing stronger to the measurement than for shorter wavelengths because of the lower probability of <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>. In addition, the radiative transfer is modified by the ozone absorption structures making longer <span class="hlt">light</span> paths less probable within strong ozone absorption bands. In this study, additional information on the spatial distribution of NO2 is investigated by analysing results obtained by Differential Optical Absorption Spectroscopy (DOAS) in various spectral fit windows. Combing the fit results in one profile retrieval algorithm helps to improve the spatial sensitivity and resolution of the measurements. The largest improvements for the spatial resolution and sensitivity are expected for the upper troposphere/ lower stratosphere (UTLS) region where the variation of the spatial sensitivity with wavelength is strongest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25679119','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25679119"><span id="translatedtitle">Fano coupling between <span class="hlt">Rayleigh</span> anomaly and localized surface plasmon resonance for sensor applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Feifei; Zhang, Xinping</p> <p>2015-06-15</p> <p>Fano coupling between <span class="hlt">Rayleigh</span> anomaly and localized surface plasmon resonance has been observed in diffractive grating structures consisting of aluminum nanolines deposited on the top surface of photoresist with each nanoline composed of tightly aggregated aluminum nanoparticles. Localized surface plasmon resonance is excited both in the nanoparticles and in the nanolines by differently polarized <span class="hlt">light</span>. The surface propagation mode excited by the first- and second-order <span class="hlt">Rayleigh</span> diffraction anomaly is strongly <span class="hlt">scattered</span> and diffracted by the plasmonic aluminum grating structures, producing <span class="hlt">light</span> rays in the same direction as the reflected <span class="hlt">light</span> beam with the same spectral feature as the <span class="hlt">Rayleigh</span> anomaly. The narrow-band diffracted and <span class="hlt">scattered</span> <span class="hlt">light</span> appears as sharp dips in the broad-band reflective optical extinction spectrum of plasmon resonance, which is recognized as a kind of Fano coupling. This kind of coupled mode is utilized successfully in refractive-index-sensor devices with excellent sensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.11801030P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.11801030P"><span id="translatedtitle">Dispersion relation for hadronic <span class="hlt">light-by-light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Procura, Massimiliano; Colangelo, Gilberto; Hoferichter, Martin; Stoffer, Peter</p> <p>2016-04-01</p> <p>The largest uncertainties in the Standard Model calculation of the anomalous magnetic moment of the muon (g - 2)μ come from hadronic contributions. In particular, in a few years the subleading hadronic <span class="hlt">light-by-light</span> (HLbL) contribution might dominate the theory uncertainty. We present a dispersive description of the HLbL tensor, which is based on unitarity, analyticity, crossing symmetry, and gauge invariance. This opens up the possibility of a data-driven determination of the HLbL contribution to (g - 2)μ with the aim of reducing model dependence and achieving a reliable error estimate. Our dispersive approach defines unambiguously the pion-pole and the pion-box contribution to the HLbL tensor. Using Mandelstam's double-spectral representation, we have proven that the pion-box contribution coincides exactly with the one-loop scalar QED amplitude, multiplied by the appropriate pion vector form factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27331616','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27331616"><span id="translatedtitle"><span class="hlt">Scattering</span> Optical Elements: Stand-Alone Optical Elements Exploiting Multiple <span class="hlt">Light</span> <span class="hlt">Scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Jongchan; Cho, Joong-Yeon; Park, Chunghyun; Lee, KyeoReh; Lee, Heon; Cho, Yong-Hoon; Park, YongKeun</p> <p>2016-07-26</p> <p>Optical design and fabrication techniques are crucial for making optical elements. From conventional lenses to diffractive optical elements and to recent metasurfaces, various types of optical elements have been proposed to manipulate <span class="hlt">light</span> where optical materials are fabricated into desired structures. Here, we propose a <span class="hlt">scattering</span> optical element (SOE) that exploits multiple <span class="hlt">light</span> <span class="hlt">scattering</span> and wavefront shaping. Instead of fabricating optical materials, the SOE consists of a disordered medium and a photopolymer-based wavefront recorder, with shapes impinging on <span class="hlt">light</span> on demand. With the proposed stand-alone SOEs, we experimentally demonstrate control of various properties of <span class="hlt">light</span>, including intensity, polarization, spectral frequency, and near field. Due to the tremendous freedom brought about by disordered media, the proposed approach will provide unexplored routes to manipulate arbitrary optical fields in stand-alone optical elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20706415','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20706415"><span id="translatedtitle">Investigation into the <span class="hlt">scattering</span> of <span class="hlt">light</span> by human hair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bustard, H K; Smith, R W</p> <p>1991-08-20</p> <p>We describe a general investigation into the <span class="hlt">scattering</span> of <span class="hlt">light</span> by human hair. The main features of the intensity distribution produced by <span class="hlt">light</span> <span class="hlt">scattered</span> by an individual hair are identified. Qualitative explanations for the features are advanced in terms of the arrangement of the outer structure of the hair and its level of pigmentation. Contrast gloss values are calculated in an attempt to quantify the appearance of hair. These values are found to depend not only on the properties of hair, such as color and condition, but also on the direction and polarization state of the incident <span class="hlt">light</span>. In assessing the effects of cosmetic treatments on hair, gloss values are shown to be useful where readings from treated hairs are compared with those from a control sample investigated in the same conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApJ...823...70T&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ApJ...823...70T&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">Scattering</span> by Fractal Dust Aggregates. I. Angular Dependence of <span class="hlt">Scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tazaki, Ryo; Tanaka, Hidekazu; Okuzumi, Satoshi; Kataoka, Akimasa; Nomura, Hideko</p> <p>2016-06-01</p> <p>In protoplanetary disks, micron-sized dust grains coagulate to form highly porous dust aggregates. Because the optical properties of these aggregates are not completely understood, it is important to investigate how porous dust aggregates <span class="hlt">scatter</span> <span class="hlt">light</span>. In this study, the <span class="hlt">light</span> <span class="hlt">scattering</span> properties of porous dust aggregates were calculated using a rigorous method, the T-matrix method, and the results were then compared with those obtained using the Rayleigh–Gans–Debye (RGD) theory and Mie theory with the effective medium approximation (EMT). The RGD theory is applicable to moderately large aggregates made of nearly transparent monomers. This study considered two types of porous dust aggregates—ballistic cluster–cluster agglomerates (BCCAs) and ballistic particle–cluster agglomerates. First, the angular dependence of the <span class="hlt">scattered</span> intensity was shown to reflect the hierarchical structure of dust aggregates; the large-scale structure of the aggregates is responsible for the intensity at small <span class="hlt">scattering</span> angles, and their small-scale structure determines the intensity at large <span class="hlt">scattering</span> angles. Second, it was determined that the EMT underestimates the backward <span class="hlt">scattering</span> intensity by multiple orders of magnitude, especially in BCCAs, because the EMT averages the structure within the size of the aggregates. It was concluded that the RGD theory is a very useful method for calculating the optical properties of BCCAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10842935','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10842935"><span id="translatedtitle">Aerosol <span class="hlt">light</span> <span class="hlt">scattering</span> measurements as a function of relative humidity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Day, D E; Malm, W C; Kreidenweis, S M</p> <p>2000-05-01</p> <p>The hygroscopic nature of atmospheric fine aerosol was investigated at a rural site in the Great Smoky Mountains National Park during July and August 1995. Passing the sample aerosol through an inlet, which housed an array of Perma Pure diffusion dryers, controlled the sample aerosol's relative humidity (RH). After conditioning the aerosol sample in the inlet, the <span class="hlt">light</span> <span class="hlt">scattering</span> coefficient and the aerosol size distribution were simultaneously measured. During this study, the conditioned aerosol's humidity ranged between 5% < RH < 95%. Aerosol response curves were produced using the ratio bspw/bspd; where bspw is the <span class="hlt">scattering</span> coefficient measured at some RH greater than 20% and bspd is the <span class="hlt">scattering</span> coefficient of the "dry" aerosol. For this work, any sample RH values below 15% were considered dry. Results of this investigation showed that the <span class="hlt">light</span> <span class="hlt">scattering</span> ratio increased continuously and smoothly over the entire range of relative humidity. The magnitude of the ratio at a particular RH value, however, varied considerably in time, particularly for RH values greater than approximately 60%. Curves of the <span class="hlt">scattering</span> coefficient ratios as a function of RH were generated for each day and compared to the average 12-hour chemical composition of the aerosol. This comparison showed that for any particular RH value the ratio was highest during time periods of high sulfate concentrations and lowest during time periods of high soil or high organic carbon concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5279604','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5279604"><span id="translatedtitle">Brillouin <span class="hlt">light</span> <span class="hlt">scattering</span> detection of ferromagnetic resonance in thin films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Srinivasan, G.; Patton, C.E.; Booth, J.G.</p> <p>1988-04-15</p> <p>Ferromagnetic resonance (FMR) in thin films of permalloy and yttrium iron garnet (YIG) has been studied by Brillouin <span class="hlt">light</span> <span class="hlt">scattering</span> (BLS) techniques. The measurements were made at 9.4 GHz on 22.4 to 75-nm-thick permalloy films and on 2.1- to 12.8-..mu..m-thick YIG films. Intensity profiles for magnon <span class="hlt">scattered</span> <span class="hlt">light</span> versus in-plane applied field were obtained by analyzing the forward <span class="hlt">scattered</span> <span class="hlt">light</span> through the films with a high-contrast Fabry--Perot interferometer. The BLS profiles show a signal-to-noise ratio of 10-100 for the permalloy and 100-1000 for the YIG films, depending on the film thickness and the microwave power level. The FMR BLS response was quantified in terms of global response function, counts/s mW versus magnon occupation number N/sub u/. The N/sub u/ parameter relates the <span class="hlt">scattering</span> to the uniform mode FMR response (linewidth, field, frequency, etc.), input microwave power, and active sample volume. The response for permalloy was approximately10/sup -8/ counts/s mW magnon, which translates into a limiting sample volume of 10/sup -12/ cm/sup 3/.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015P%26SS..118..164M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015P%26SS..118..164M"><span id="translatedtitle">Inhomogeneous particle model for <span class="hlt">light-scattering</span> by cometary dust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Markkanen, Johannes; Penttilä, Antti; Peltoniemi, Jouni; Muinonen, Karri</p> <p>2015-12-01</p> <p>We introduce an inhomogeneous irregular-particle model for reproducing the typical <span class="hlt">light-scattering</span> features of cometary dust such as the negative polarization near the backscattering direction, and the weak increase of the backscattering intensity. The model is based on the hierarchical Voronoi-partitioning and the algorithm provides fast generation of irregular particles with a flexible control of inhomogeneity. The input parameters of the model are refractive indices, their volumetric abundances, and the number of constituents on each level. The <span class="hlt">light-scattering</span> properties of these particles with parameters relevant to cometary dust are solved by the volume-integral-equation method. The <span class="hlt">light-scattering</span> features of inhomogeneous particles are compared with the mixtures of homogeneous particles, and particles with the refractive index obtained by the effective-medium approximation. We show that with the inhomogeneity size of order 0.2 μm, the different models produce qualitatively similar <span class="hlt">scattering</span> features while some quantitative differences are observed which have an effect on the retrieved material composition of dust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8592E..17T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8592E..17T"><span id="translatedtitle">Depolarization of <span class="hlt">light</span> by rough surface of <span class="hlt">scattering</span> phantoms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tchvialeva, Lioudmila; Markhvida, Igor; Lee, Tim K.; Doronin, Alexander; Meglinski, Igor</p> <p>2013-02-01</p> <p>The growing interest in biomedical optics to the polarimetric methods push researchers to better understand of <span class="hlt">light</span> depolarization during <span class="hlt">scattering</span> in and on the surface of biological tissues. Here we study the depolarization of <span class="hlt">light</span> propagated in silicone phantoms. The phantoms with variety of surface roughness and bulk optical properties are designed to imitate human skin. Free-space speckle patterns in parallel (III) and perpendicular (I⊥) direction in respect to incident polarization are used to get the depolarization ratio of backscattered <span class="hlt">light</span> DR = (III - I⊥)/( III + I⊥). The Monte Carlo model developed in house is also applied to compare simulated DR with experimentally measured. DR dependence on roughness, concentration and size of <span class="hlt">scattering</span> particles is analysed. A weak depolarization and negligible response to <span class="hlt">scattering</span> of the medium are observed for phantoms with smooth surfaces, whereas for the surface roughness in order to the mean free path the depolarization ratio decreases and reveals dependence on the bulk <span class="hlt">scattering</span> coefficient. In is shown that the surface roughness could be a key factor triggering the ability of tissues' characterization by depolarization ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1458M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1458M"><span id="translatedtitle">Modeling <span class="hlt">light</span> <span class="hlt">scattering</span> by mineral dust particles using spheroids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merikallio, Sini; Nousiainen, Timo</p> <p></p> <p>Suspended dust particles have a considerable influence on <span class="hlt">light</span> <span class="hlt">scattering</span> in both terrestrial and planetary atmospheres and can therefore have a large effect on the interpretation of remote sensing measurements. Assuming dust particles to be spherical is known to produce inaccurate results when modeling optical properties of real mineral dust particles. Yet this approximation is widely used for its simplicity. Here, we simulate <span class="hlt">light</span> <span class="hlt">scattering</span> by mineral dust particles using a distribution of model spheroids. This is done by comparing <span class="hlt">scattering</span> matrices calculated from a dust optical database of Dubovik et al. [2006] with those measured in the laboratory by Volten et al. [2001]. Wavelengths of 441,6 nm and 632,8 nm and refractive indexes of Re = 1.55 -1.7 and Im = 0.001i -0.01i were adopted in this study. Overall, spheroids are found to fit the measurements significantly better than Mie spheres. Further, we confirm that the shape distribution parametrization developed in Nousiainen et al. (2006) significantly improves the accuracy of simulated single-<span class="hlt">scattering</span> for small mineral dust particles. The spheroid scheme should therefore yield more reliable interpretations of remote sensing data from dusty planetary atmospheres. While the spheroidal scheme is superior to spheres in remote sensing applications, its performance is far from perfect especially for samples with large particles. Thus, additional advances are clearly possible. Further studies of the Martian atmosphere are currently under way. Dubovik et al. (2006) Application of spheroid models to account for aerosol particle nonspheric-ity in remote sensing of desert dust, JGR, Vol. 111, D11208 Volten et al. (2001) <span class="hlt">Scattering</span> matrices of mineral aerosol particles at 441.6 nm and 632.8 nm, JGR, Vol. 106, No. D15, pp. 17375-17401 Nousiainen et al. (2006) <span class="hlt">Light</span> <span class="hlt">scattering</span> modeling of small feldspar aerosol particles using polyhedral prisms and spheroids, JQSRT 101, pp. 471-487</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.7061E..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.7061E..02L"><span id="translatedtitle">Free-form thin lens design with <span class="hlt">light</span> <span class="hlt">scattering</span> surfaces for practical LED down <span class="hlt">light</span> illumination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Raychiy J.; Sun, Ching-Cherng</p> <p>2016-05-01</p> <p>The free-form optical quasilens surface technology was utilized to develop and design a solid transparent plastic optical lens for the LED down <span class="hlt">light</span> with the narrow angular <span class="hlt">light</span> distribution requirement in the LED <span class="hlt">lighting</span> applications. In order to successfully complete the mission, the precise mid-field angular distribution model of the LED <span class="hlt">light</span> source was established and built. And also the optical <span class="hlt">scattering</span> surface property of the Harvey BSDF <span class="hlt">scattering</span> model was designed, measured, and established. Then, the optical simulation for the entire optical system was performed to develop and design this solid transparent plastic optical lens system. Finally, the goals of 40 deg angular <span class="hlt">light</span> distribution pattern defined at full width half maximum with glare reduced in the areas of interest and the optical performance of nearly 82% <span class="hlt">light</span> energy transmission optics were achieved for the LED down <span class="hlt">light</span> illumination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5147..370P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5147..370P"><span id="translatedtitle">Laser <span class="hlt">light-scattering</span> diagnostic of blood protein solutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petrova, Galina P.; Petrusevich, Yurii M.; Ten, Dmitrii I.; Boiko, A. V.; Fadyukova, Olga E.</p> <p>2003-11-01</p> <p>Molecular methods of diagnostics of widespread diseases including vascular pathology on the base static and dynamic laser <span class="hlt">light</span> <span class="hlt">scattering</span> in serum blood solution are testified. The alterations of molecular parameters of blood serum of animal species (rats) after experimentally induced cerebral ischemia (hypoxia) and haemorrhagic stroke relative to controls were studied. It was obtained that effective mass of <span class="hlt">scattering</span> particles in blood serum solutions is diminished for haemorrhagic and ischemic rats in comparison to control. The relative protein concentrations in blood serum also change both after false operation and in case of induced ischemia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/387021','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/387021"><span id="translatedtitle">Halos and rainbows: The elastic <span class="hlt">scattering</span> of <span class="hlt">light</span> exotic nuclei</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Satchler, G.R.; Hussein, M.H.</p> <p>1993-10-01</p> <p>The <span class="hlt">scattering</span> of an exotic <span class="hlt">light</span> nucleus with a halo is compared with that of a normal nucleus. Four, sometimes opposing effects arising from the halo are identified. Semiclassical expressions are derived which embody these effects. The cases of {sup 11}Li and {sup 11}C <span class="hlt">scattering</span> from {sup 12}C at E/A = 60 MeV are compared. We conclude that the {sup 11}Li differential cross sections are probably smaller than those for {sup 11}C, in agreement with recent analyses of the measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21439544','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21439544"><span id="translatedtitle">Debye series for <span class="hlt">light</span> <span class="hlt">scattering</span> by a coated nonspherical particle</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xu Feng; Lock, James A.</p> <p>2010-06-15</p> <p>By using the extended boundary condition method, the Debye series is developed for <span class="hlt">light</span> <span class="hlt">scattered</span> by a coated nonspherical particle in order to interpret the angular dependence of the <span class="hlt">scattered</span> intensity in terms of various physical processes. Numerical calculations are performed to study the influence of the coating thickness and the ellipticity of a coated spheroid on the angular position of the {alpha} and {beta} primary rainbows, which are produced by partial waves experiencing one internal reflection. The hyperbolic umbilic focal section is demonstrated and is analyzed for both the {alpha} and the {beta} rainbows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010PhRvA..81f3812X&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010PhRvA..81f3812X&link_type=ABSTRACT"><span id="translatedtitle">Debye series for <span class="hlt">light</span> <span class="hlt">scattering</span> by a coated nonspherical particle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Feng; Lock, James A.</p> <p>2010-06-01</p> <p>By using the extended boundary condition method, the Debye series is developed for <span class="hlt">light</span> <span class="hlt">scattered</span> by a coated nonspherical particle in order to interpret the angular dependence of the <span class="hlt">scattered</span> intensity in terms of various physical processes. Numerical calculations are performed to study the influence of the coating thickness and the ellipticity of a coated spheroid on the angular position of the α and β primary rainbows, which are produced by partial waves experiencing one internal reflection. The hyperbolic umbilic focal section is demonstrated and is analyzed for both the α and the β rainbows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT.......117H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT.......117H"><span id="translatedtitle">In situ measurement of inelastic <span class="hlt">light</span> <span class="hlt">scattering</span> in natural waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, Chuanmin</p> <p></p> <p>Variation in the shape of solar absorption (Fraunhofer) lines are used to study the inelastic <span class="hlt">scattering</span> in natural waters. In addition, oxygen absorption lines near 689nm are used to study the solar stimulated chlorophyll fluorescence. The prototype Oceanic Fraunhofer Line Discriminator (OFLD) has been further developed and improved by using a well protected fiber optic - wire conductor cable and underwater electronic housing. A Monte-Carlo code and a simple code have been modified to simulate the Raman <span class="hlt">scattering</span>, DOM fluorescence and chlorophyll fluorescence. A series of in situ measurements have been conducted in clear ocean waters in the Florida Straits, in the turbid waters of Florida Bay, and in the vicinity of a coral reef in the Dry Tortugas. By comparing the reduced data with the model simulation results, the Raman <span class="hlt">scattering</span> coefficient, b r with an excitation wavelength at 488nm, has been verified to be 2.6 × 10-4m-1 (Marshall and Smith, 1990), as opposed to 14.4 × 10- 4m-1 (Slusher and Derr, 1975). The wavelength dependence of b r cannot be accurately determined from the data set as the reported values (λ m-4 to λ m- 5) have an insignificant effect in the natural underwater <span class="hlt">light</span> field. Generally, in clear water, the percentage of inelastic <span class="hlt">scattered</span> <span class="hlt">light</span> in the total <span class="hlt">light</span> field at /lambda < 510nm is negligible for the whole water column, and this percentage increases with depth at /lambda > 510nm. At low concentrations (a y(/lambda = 380nm) less than 0.1m-1), DOM fluorescence plays a small role in the inelastic <span class="hlt">light</span> field. However, chlorophyll fluorescence is much stronger than Raman <span class="hlt">scattering</span> at 685nm. In shallow waters where a sea bottom affects the ambient <span class="hlt">light</span> field, inelastic <span class="hlt">light</span> is negligible for the whole visible band. Since Raman <span class="hlt">scattering</span> is now well characterized, the new OFLD can be used to measure the solar stimulated in situ fluorescence. As a result, the fluorescence signals of various bottom surfaces, from coral to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873717','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873717"><span id="translatedtitle">Paper area density measurement from forward transmitted <span class="hlt">scattered</span> <span class="hlt">light</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Koo, Jackson C.</p> <p>2001-01-01</p> <p>A method whereby the average paper fiber area density (weight per unit area) can be directly calculated from the intensity of transmitted, <span class="hlt">scattered</span> <span class="hlt">light</span> at two different wavelengths, one being a non-absorpted wavelength. Also, the method makes it possible to derive the water percentage per fiber area density from a two-wavelength measurement. In the optical measuring technique optical transmitted intensity, for example, at 2.1 microns cellulose absorption line is measured and compared with another <span class="hlt">scattered</span>, optical transmitted intensity reference in the nearby spectrum region, such as 1.68 microns, where there is no absorption. From the ratio of these two intensities, one can calculate the <span class="hlt">scattering</span> absorption coefficient at 2.1 microns. This absorption coefficient at this wavelength is, then, experimentally correlated to the paper fiber area density. The water percentage per fiber area density can be derived from this two-wavelength measurement approach.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12006027','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12006027"><span id="translatedtitle">Analysis of Thomson <span class="hlt">scattered</span> <span class="hlt">light</span> from an arc plasma jet.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gregori, G; Kortshagen, U; Heberlein, J; Pfender, E</p> <p>2002-04-01</p> <p>In this paper we present an analysis of Thomson <span class="hlt">scattered</span> <span class="hlt">light</span> from an arc plasma jet. Our approach goes beyond the standard random-phase approximation (RPA) and provides more consistent data for the electron temperature and density in plasmas that are weakly nonideal and collisional. The theory is based on a memory function formalism for the spectral density function with the use of the three lowest-order frequency-moment sum rules. These moments are then corrected for temperature inhomogeneities in the <span class="hlt">scattering</span> volume. The proposed interpretation of <span class="hlt">scattering</span> data is compared with the RPA result and with the standard Bhatnagar-Gross-Krook collisional model for the dynamic structure factor. It is shown that the obtained electron temperature values are closer but not equal to local thermodynamic equilibrium temperature values extracted from spectroscopic measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14686511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14686511"><span id="translatedtitle">Comparison of the auxiliary function method and the discrete-ordinate method for solving the radiative transfer equation for <span class="hlt">light</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Silva, Anabela; Elias, Mady; Andraud, Christine; Lafait, Jacques</p> <p>2003-12-01</p> <p>Two methods for solving the radiative transfer equation are compared with the aim of computing the angular distribution of the <span class="hlt">light</span> <span class="hlt">scattered</span> by a heterogeneous <span class="hlt">scattering</span> medium composed of a single flat layer or a multilayer. The first method [auxiliary function method (AFM)], recently developed, uses an auxiliary function and leads to an exact solution; the second [discrete-ordinate method (DOM)] is based on the channel concept and needs an angular discretization. The comparison is applied to two different media presenting two typical and extreme <span class="hlt">scattering</span> behaviors: <span class="hlt">Rayleigh</span> and Mie <span class="hlt">scattering</span> with smooth or very anisotropic phase functions, respectively. A very good agreement between the predictions of the two methods is observed in both cases. The larger the number of channels used in the DOM, the better the agreement. The principal advantages and limitations of each method are also listed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2270354','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2270354"><span id="translatedtitle">Neutron activation analysis and X-ray <span class="hlt">Rayleigh</span> and Raman <span class="hlt">scattering</span> of hair and nail clippings as noninvasive bioindicators for Cu liver status in Labrador Retrievers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bueno, Maria Izabel Maretti Silveira; Bortoleto, Gisele G.; Hoffmann, Gaby; van den Ingh, Ted S. G. A. M.; Rothuizen, Jan</p> <p>2008-01-01</p> <p>The heritability of chronic hepatitis in the Labrador Retriever is studied with the aim of identifying the related gene mutation. Identification of cases and controls is largely based on instrumental neutron activation analysis (INAA) Cu determination in liver biopsies. The burden for these companion animals may be reduced if nail clippings and hair (fur) could serve as a noninvasive indicator for the hepatic Cu concentrations. No correlation was found between hepatic Cu concentrations and Cu concentrations in hair and nail samples. However, hair and nail samples were also analyzed by X-ray tube excitation, taking advantage of the X-ray Compton, <span class="hlt">Rayleigh</span>, and Raman <span class="hlt">scattering</span> which reflects the organic components such as the type of melanin. Principal component analysis provided first indications that some differentiation between healthy and sick dogs could indeed be obtained from hair and nail analysis. Figure Principal component analysis of <span class="hlt">scattered</span> region of x-ray fluorescence spectra of Labrador dog nails, demonstrating the differentiation towards dogs with high and low Cu liver levels (respectively positive and negative PC2 values) reflecting hepatitis, as well as gender (PC1: negative values for female and positive values for males) PMID:18264701</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApSS..314..858Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApSS..314..858Z"><span id="translatedtitle"><span class="hlt">Light</span> extraction enhancement from organic <span class="hlt">light</span>-emitting diodes with randomly <span class="hlt">scattered</span> surface fixture</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Dong-Ying; Shi, Xiao-Bo; Gao, Chun-Hong; Cai, Shi-Duan; Jin, Yue; Liao, Liang-Sheng</p> <p>2014-09-01</p> <p>A combination of a <span class="hlt">scattering</span> medium layer and a roughened substrate was proposed to enhance the <span class="hlt">light</span> extraction efficiency of organic <span class="hlt">light</span>-emitting diodes (OLEDs). Comparing with a reference OLED without any <span class="hlt">scattering</span> layer, 65% improvement in the forward emission has been achieved with a <span class="hlt">scattering</span> layer formed on an intentionally roughened external substrate surface of the OLED by spin-coating a sol-gel fabricated matrix containing well dispersed titania (TiO2) particles. Such a combination method not only demonstrated efficient extraction of the <span class="hlt">light</span> trapped in the glass substrate but also achieved homogenous emission from the OLED panel. The proposed technique, convenient and inexpensive, is believed to be suitable for the large area OLED production in <span class="hlt">lighting</span> applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830050808&hterms=ghost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dghost','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830050808&hterms=ghost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dghost"><span id="translatedtitle">Space telescope low <span class="hlt">scattered</span> <span class="hlt">light</span> camera - A model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Breckinridge, J. B.; Kuper, T. G.; Shack, R. V.</p> <p>1982-01-01</p> <p>A design approach for a camera to be used with the space telescope is given. Camera optics relay the system pupil onto an annular Gaussian ring apodizing mask to control <span class="hlt">scattered</span> <span class="hlt">light</span>. One and two dimensional models of ripple on the primary mirror were calculated. <span class="hlt">Scattered</span> <span class="hlt">light</span> calculations using ripple amplitudes between wavelength/20 wavelength/200 with spatial correlations of the ripple across the primary mirror between 0.2 and 2.0 centimeters indicate that the detection of an object a billion times fainter than a bright source in the field is possible. Detection of a Jovian type planet in orbit about alpha Centauri with a camera on the space telescope may be possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..899..808C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..899..808C"><span id="translatedtitle">A Possible Application of Coherent <span class="hlt">Light</span> <span class="hlt">Scattering</span> on Biological Fluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chicea, Dan; Chicea, Liana Maria</p> <p>2007-04-01</p> <p>Human urine from both healthy patients and patients with different diseases was used as <span class="hlt">scattering</span> medium in a coherent <span class="hlt">light</span> <span class="hlt">scattering</span> experiment. The time variation of the <span class="hlt">light</span> intensity in the far field speckle image was acquired using a data acquisition system on a PC and a time series resulted for each sample. The autocorrelation function for each sample was calculated and the autocorrelation time was determined. The same samples were analyzed in a medical laboratory using the standard procedure. We found so far that the autocorrelation time is differently modified by the presence of pus, albumin, urobilin and sediments. The results suggest a fast procedure that can be used as laboratory test to detect the presence not of each individual component in suspensions but of big conglomerates as albumin, cylinders, oxalate crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991PrOce..28..343S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991PrOce..28..343S"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> by microorganisms in the open ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stramski, Dariusz; Kiefer, Dale A.</p> <p></p> <p>Recent enumeration and identification of marine particles that are less than 2μm in diameter, suggests that they may be the major source of <span class="hlt">light</span> <span class="hlt">scattering</span> in the open ocean. The living components of these small particles include viruses, heterotrophic and photoautotrophic bacteria and the smallest eucaryotic cells. In order to examine the relative contribution by these (and other) microorganisms to <span class="hlt">scattering</span>, we have calculated a budget for both the total <span class="hlt">scattering</span> and backscattering coefficients (at 550nm) of suspended particles. This budget is determined by calculating the product of the numerical concentration of particles of a given category and the <span class="hlt">scattering</span> cross-section of that category. Values for this product are then compared to values for the particulate <span class="hlt">scattering</span> coefficients predicted by the models of GORDON and MOREL (1983) and MOREL (1988). In order to make such a comparison, we have estimated both the total <span class="hlt">scattering</span> and backscattering cross-section of various microbial components that include viruses, heterotrophic bacteria, prochlorophytes, cyanobacteria, ultrananoplankton (2-8μm), larger nanoplankton (8-20μm) and microplankton (>20 μm). Such determinations are based upon Mie <span class="hlt">scattering</span> calculations and measurements of the cell size distribution and the absorption and <span class="hlt">scattering</span> coefficients of microbial cultures. In addition, we have gathered published information on the numerical concentration of living and detrial marine particles in the size range from 0.03 to 100μm. The results of such a study are summarized as follows. The size distribution of microorganisms in the ocean roughly obeys an inverse 4th power law over three orders of magnitude in cell diameter, from 0.2 to 100μm. Thus, the size distribution of living organisms is similar to that for total particulate matter as determined by electronic particle counters. For representative values of refractive index, it appears that most of the <span class="hlt">scattering</span> in the sea comes from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/171365','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/171365"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> studies of an electrorheological fluid in oscillatory shear</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martin, J.E.; Odinek, J.</p> <p>1995-12-31</p> <p>We have conducted a real time, two-dimensional <span class="hlt">light</span> <span class="hlt">scattering</span> study of the nonlinear dynamics of field-induced structures in an electrorheological fluid subjected to oscillatory shear. We have developed a kinetic chain model of the observed dynamics by considering the response of a fragmenting/aggregating particle chain to the prevailing hydrodynamic and electrostatic forces. This structural theory is then used to describe the nonlinear rheology of ER fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/662693','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/662693"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> measurements supporting helical structures for chromatin in solution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campbell, A M; Cotter, R I; Pardon, J F</p> <p>1978-05-01</p> <p>Laser <span class="hlt">light</span> <span class="hlt">scattering</span> measurements have been made on a series of polynucleosomes containing from 50 to 150 nucleosomes. Radii of gyration have been determined as a function of polynucleosome length for different ionic strength solutions. The results suggest that at low ionic strength the chromatin adopts a loosely helical structure rather than a random coil. The helix becomes more regular on increasing the ionic strength, the dimension resembling those proposed by Finch and Klug for their solenoid model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920024981','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920024981"><span id="translatedtitle">Development of a versatile laser <span class="hlt">light</span> <span class="hlt">scattering</span> instrument</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meyer, William V.; Ansari, Rafat R.</p> <p>1992-01-01</p> <p>NASA Lewis Research Center is providing and coordinating the technology for placing a compact Laser <span class="hlt">Light</span> <span class="hlt">Scattering</span> (LLS) instrument in a microgravity environment. This will be accomplished by defining and assessing user requirements for microgravity experiments, coordinating needed technological developments, and filling technical gaps. This effort is striving to brassboard and evaluate a miniature multi-angle LLS instrument. The progress of the program is reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26625022','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26625022"><span id="translatedtitle"><span class="hlt">Light</span> source for narrow and broadband coherent Raman <span class="hlt">scattering</span> microspectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brinkmann, Maximilian; Dobner, Sven; Fallnich, Carsten</p> <p>2015-12-01</p> <p>We present a <span class="hlt">light</span> source that is well adapted to both narrow- and broadband coherent Raman <span class="hlt">scattering</span> (CRS) methods. Based on a single oscillator, the <span class="hlt">light</span> source delivers synchronized broadband pulses via supercontinuum generation and narrowband, frequency-tunable pulses via four-wave mixing in a photonic crystal fiber. Seeding the four-wave mixing with a spectrally filtered part of the supercontinuum yields high-pulse energies up to 8 nJ and the possibility of scanning a bandwidth of 2000  cm(-1) in 25 ms. All pulses are emitted with a repetition frequency of 1 MHz, which ensures efficient generation of CRS signals while avoiding significant damage of the samples. Consequently, the <span class="hlt">light</span> source combines the performance of individual narrow- and broadband CRS <span class="hlt">light</span> sources in one setup, thus enabling hyperspectral imaging and rapid single-resonance imaging in parallel. PMID:26625022</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1223098','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1223098"><span id="translatedtitle">Photovoltaic structures having a <span class="hlt">light</span> <span class="hlt">scattering</span> interface layer and methods of making the same</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, Xiangxin; Compaan, Alvin D.; Paudel, Naba Raj</p> <p>2015-10-13</p> <p>Photovoltaic (PV) cell structures having an integral <span class="hlt">light</span> <span class="hlt">scattering</span> interface layer configured to diffuse or <span class="hlt">scatter</span> <span class="hlt">light</span> prior to entering a semiconductor material and methods of making the same are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AcSpA.105..612W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AcSpA.105..612W"><span id="translatedtitle">Study on the interactions of antiemetic drugs and 12-tungstophosphoric acid by absorption and resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> spectra and their analytical applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yaqiong; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Hu, Xiaoli</p> <p>2013-03-01</p> <p>In 0.1 mol L-1 HCl medium, antiemetic drugs (ATM), such as granisetron hydrochloride (GS) and tropisetron hydrochloride (TS), reacted with H3PW12O40·nH2O and formed 3:1 ion-association complex of [(ATM)3PW12O40], then self-aggregated into nanoparticles-[(ATM)3PW12O40]n with an average size of 100 nm. The reaction resulted in the enhancement of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) and the absorption spectra. The increments of <span class="hlt">scattering</span> intensity (ΔIRRS) and the change of absorbance (ΔA) were both directly proportional to the concentrations of ATM in certain ranges. Accordingly, two new RRS and spectrophotometric methods were proposed for ATM detection. The detection limits (3σ) of GS and TS were 3.2 ng mL-1 and 4.0 ng mL-1(RRS method), 112.5 ng mL-1 and 100.0 ng mL-1(spectrophotometric method). These two methods were applied to determine GS in orally disintegrating tablets and the results were in good agreement with the official method. The ground-state geometries and electronic structures of GS and TS were optimized by the hybrid density functional theory (DFT) method and the shape of [(ATM)3PW12O40]n was characterized by atomic force microscopy (AFM). Take the RRS method with higher sensitivity as an example, the reaction mechanism and the reasons for enhancement of <span class="hlt">scattering</span> were discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/985482','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/985482"><span id="translatedtitle">Advanced Compton <span class="hlt">scattering</span> <span class="hlt">light</span> source R&D at LLNL</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Albert, F; Anderson, S G; Anderson, G; Betts, S M; Chu, T S; Gibson, D J; Marsh, R A; Messerly, M; Shverdin, M Y; Wu, S; Hartemann, F V; Siders, C W; Barty, C P</p> <p>2010-02-16</p> <p>We report the design and current status of a monoenergetic laser-based Compton <span class="hlt">scattering</span> 0.5-2.5 MeV {gamma}-ray source. Previous nuclear resonance fluorescence results and future linac and laser developments for the source are presented. At MeV photon energies relevant for nuclear processes, Compton <span class="hlt">scattering</span> <span class="hlt">light</span> sources are attractive because of their relative compactness and improved brightness above 100 keV, compared to typical 4th generation synchrotrons. Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable Mono-Energetic Gamma-Ray (MEGa-Ray) <span class="hlt">light</span> sources based on Compton <span class="hlt">scattering</span> between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A new precision, tunable gamma-ray source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton <span class="hlt">scattering</span>. Based on the success of the previous Thomson-Radiated Extreme X-rays (T-REX) Compton <span class="hlt">scattering</span> source at LLNL, the source will be used to excite nuclear resonance fluorescence lines in various isotopes; applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. After a brief presentation of successful nuclear resonance fluorescence (NRF) experiments done with T-REX, the new source design, key parameters, and current status are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1133128','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1133128"><span id="translatedtitle">Efficient <span class="hlt">Light</span> Extraction from Organic <span class="hlt">Light</span>-Emitting Diodes Using Plasmonic <span class="hlt">Scattering</span> Layers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rothberg, Lewis</p> <p>2012-11-30</p> <p>Our project addressed the DOE MYPP 2020 goal to improve <span class="hlt">light</span> extraction from organic <span class="hlt">light</span>-emitting diodes (OLEDs) to 75% (Core task 6.3). As noted in the 2010 MYPP, “the greatest opportunity for improvement is in the extraction of <span class="hlt">light</span> from [OLED] panels”. There are many approaches to avoiding waveguiding limitations intrinsic to the planar OLED structure including use of textured substrates, microcavity designs and incorporating <span class="hlt">scattering</span> layers into the device structure. We have chosen to pursue <span class="hlt">scattering</span> layers since it addresses the largest source of loss which is waveguiding in the OLED itself. <span class="hlt">Scattering</span> layers also have the potential to be relatively robust to color, polarization and angular distributions. We note that this can be combined with textured or microlens decorated substrates to achieve additional enhancement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..SES..GA03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..SES..GA03K"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">Scattering</span> and Absorption Studies of Sickle Cell Hemoglobin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim-Shapiro, Daniel</p> <p>1997-11-01</p> <p>The use of physical techniques has been very important in understanding the pathophysiology of sickle cell disease. In particular, <span class="hlt">light</span> <span class="hlt">scattering</span> and absorption studies have been used to measure the kinetics of sickle cell hemoglobin polymerization and depolymerization (melting). The theory of sickle cell polymerization that has been derived and tested by these methods has not only led to an increased understanding of the pathophysiology of the disease but has also led to improved treatment strategies. Sickle cell disease effects about 1 out of 600 people of African descent born in the United States. The disease is caused by a mutant form of hemoglobin (the oxygen transporting molecule in the blood), hemoglobin S (HbS), which differs from normal adult hemoglobin by the substitution of a single amino acid for another. The polymerization of HbS, which occurs under conditions of low oxygen pressure, causes distortion and increased rigidity of the sickle red blood cell that leads to blockage of the capillaries and a host of resulting complications. The disease is associated with tissue damage, severe painful crises and a high degree of mortality. <span class="hlt">Light</span> <span class="hlt">scattering</span> studies of purified HbS and whole cells (conducted by F.A. Ferrone, J. Hofrichter, W.A. Eaton, and their associates) have been used to determine the mechanism of HbS polymerization. Polymerization will generally not occur when the hemoglobin is in an oxygen-rich environment. The question is, when HbS is rapidly deoxygenated (as it is when going from the lungs to the tissues) what is the kinetics of polymerization? Photolysis methods were used to rapidly deoxygenate HbS and <span class="hlt">light</span> <span class="hlt">scattering</span> was used as a function of time to measure the kinetics of polymerization. Polarized <span class="hlt">light</span> <span class="hlt">scattering</span> may be a more effective way to measure polymer content than total intensity <span class="hlt">light</span> <span class="hlt">scattering</span>. It was found that no polymerization occurs during a period of time called the delay time and subsequent polymerization occurs</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DPS....4721307P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DPS....4721307P"><span id="translatedtitle">Explaining Space-Weathering Effects on UV-Vis-NIR Spectra with <span class="hlt">Light-Scattering</span> Methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Penttilä, Antti; Väisänen, Timo; Martikainen, Julia; Kohout, Tomas; Muinonen, Karri</p> <p>2015-11-01</p> <p>Space-weathering (SW) introduces changes to the asteroid reflectance spectra. In silicate minerals, SW is known to darken the spectra and reduce the silicate absorption band depths. In olivine, the neutral slope in Vis and NIR wavelengths is becoming positive [1]. In pyroxene, the positive slope over the 1 µm absorption band is decreasing, and the negative slope over the 2 µm band is increasing towards positive values with increasing SW [2].The SW process generates small nanophase iron (npFe0) inclusions in the surface layers of mineral grains. The inclusions are some tens of nm in size. This mechanism has been linked to the Moon and to a certain extent also to the silicate-rich S-complex asteroids.We offer two simple explanations from <span class="hlt">light-scattering</span> theory to explain the SW effects on the spectral slope. First, the npFe0 will introduce a posititive general slope (reddening) to the spectra. The npFe0 inclusions (~10 nm) are in the <span class="hlt">Rayleigh</span> domain with the wavelength λ in the UV-Vis-NIR range. Their absorption cross-section follows approximately the 1/λ-relation from the <span class="hlt">Rayleigh</span> theory. Absorption is more efficient in the UV than in the NIR wavelengths, therefore the spectra are reddening.Second, the effect of npFe0 absorption is more efficient for originally brighter reflectance values. Explanation combines the effective medium theory and the exponential attenuation in the medium. When adding a small amount of highly absorbing npFe0, the effective absorption coefficient k will increase approximately the same Δk for the typical values of silicates. This change will increase more effectively the exponential attenuation if the original k was very small, and thus the reflectance high. Therefore, both positive and negative spectral slopes will approach zero with SW.We conclude that the SW will introduce a general reddening, and neutralize local slopes. This is verified using the SIRIS code [3], which combines geometric optics with small internal diffuse</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17361300','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17361300"><span id="translatedtitle"><span class="hlt">Scattered</span> <span class="hlt">light</span> corrections to Sun photometry: analytical results for single and multiple <span class="hlt">scattering</span> regimes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kokhanovsky, Alexander A</p> <p>2007-04-01</p> <p>Analytical equations for the diffused <span class="hlt">scattered</span> <span class="hlt">light</span> correction factor of Sun photometers are derived and analyzed. It is shown that corrections are weakly dependent on the atmospheric optical thickness. They are influenced mostly by the size of aerosol particles encountered by sunlight on its way to a Sun photometer. In addition, the accuracy of the small-angle approximation used in the work is studied with numerical calculations based on the exact radiative transfer equation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7074199','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7074199"><span id="translatedtitle">Motility analysis of circularly swimming bull spermatozoa by quasi-elastic <span class="hlt">light</span> <span class="hlt">scattering</span> and cinematography.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Craig, T; Hallett, F R; Nickel, B</p> <p>1982-04-01</p> <p>The <span class="hlt">Rayleigh</span>-Gans-Debye approximation is used to predict the electric field autocorrelation functions of <span class="hlt">light</span> <span class="hlt">scattered</span> from circularly swimming bull spermatozoa. Using parameters determined from cinematography and modeling the cells as coated ellipsoids of semiaxes a = 0.5 micrometers, b = 2.3 micrometers, and c = 9.0 micrometers, we were able to obtain model spectra that mimic the data exactly. A coat is found to be a necessary attribute of the particle. It is also clear that these model functions at 15 degrees may be represented by the relatively simple function used before by Hallett et al. (1978) to fit data from circularly swimming cells, thus giving some physical meaning to these functional shapes. Because of this agreement the half-widths of experimental functions can now be interpreted in terms of an oscillatory frequency for the movement of the circularly swimming cell. The cinematographic results show a trend to chaotic behavior as the temperature of the sample is increased, with concomitant decrease in overall efficiency. This is manifested by a decrease in oscillatory frequency and translational speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010SPIE.7469E..0OC&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010SPIE.7469E..0OC&link_type=ABSTRACT"><span id="translatedtitle">Investigating nanoparticle aggregation dynamics in an aqueous magnetic fluid by <span class="hlt">light</span> <span class="hlt">scattering</span> anisotropy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chicea, Dan</p> <p>2010-05-01</p> <p><span class="hlt">Light</span> <span class="hlt">scattering</span> on particles having the diameter comparable with the wavelength is accurately described by the Mie theory and the <span class="hlt">light</span> <span class="hlt">scattering</span> anisotropy can conveniently be described by the one parameter Henyey Greenstein phase function. An aqueous suspension containing magnetite nanoparticles was the target of a coherent <span class="hlt">light</span> <span class="hlt">scattering</span> experiment. By fitting the <span class="hlt">scattering</span> phase function on the experimental data the <span class="hlt">scattering</span> anisotropy parameter can be assessed. As the <span class="hlt">scattering</span> parameter strongly depends of the <span class="hlt">scatterer</span> size, the average particle diameter was thus estimated and particle aggregates presence was probed. This technique was used to investigate the nanoparticle aggregation dynamics and the results are presented in this work.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6574688','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6574688"><span id="translatedtitle">Studies of toxic aerosols via elastic and inelastic <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Foss, W.; Li, W.; Allen, T.M.; Blair, D.S.; Davis, E.J. )</p> <p>1993-02-01</p> <p>Evaporation rates and chemical characteristics of potentially toxic aerosols have been determined by elastic and inelastic <span class="hlt">light-scattering</span> measurements. The aerosol systems examined were a commercial catalyst consisting of a mixture of stannous octanoate (SNO) and 2-ethylhexanoic acid (EHA) and droplets emitted from open tanks of chromic acid solutions used for anodizing aluminum. The heavy metals contained in these aerosols represent a danger to the workplace if such materials are inhaled. Nanogram amounts of the solutions were studied by suspending single microdroplets in electrodynamic balances in a flow of air to measure evaporation rates and to obtain Raman spectra. Elastic <span class="hlt">scattering</span> data include phase functions and morphological resonance spectra from which droplet sizes are determined. The inelastic <span class="hlt">light-scattering</span> data or Raman spectra provide molecular vibrational bond information. It was found that EHA spectra agree with bulk data in the literature, and that SNO Raman spectra, which are not available in the literature, are consistent with infrared spectra for bulk SNO. At room temperature the vapor pressure of SNO is on the order of 0.01 Pa while that of EHA is on the order of 0.1 Pa. Raman data for the residue of evaporated chromic acid solutions show the presence of chromium oxides (Cr[sup 6+] compounds), surfactants, and bound (nonvolatile) water. 31 refs., 14 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25760756','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25760756"><span id="translatedtitle">Overview of single-cell elastic <span class="hlt">light</span> <span class="hlt">scattering</span> techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kinnunen, Matti; Karmenyan, Artashes</p> <p>2015-05-01</p> <p>We present and discuss several modern optical methods based on elastic <span class="hlt">light</span> <span class="hlt">scattering</span> (ELS), along with their technical features and applications in biomedicine and life sciences. In particular, we review some ELS experiments at the single-cell level and explore new directions of applications. Due to recent developments in experimental systems (as shown in the literature), ELS lends itself to useful applications in the life sciences. Of the developed methods, we cover elastic <span class="hlt">scattering</span> spectroscopy, optical tweezer-assisted measurement, goniometers, Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span> (FTLS), and microscopic methods. FTLS significantly extends the potential analysis of single cells by allowing monitoring of dynamical changes at the single-cell level. The main aim of our review is to demonstrate developments in the experimental investigation of ELS in single cells including issues related to theoretical “representations” and modeling of biological systems (cells, cellular systems, tissues, and so on). Goniometric measurements of ELS from optically trapped single cells are shown and the importance of the experimental verification of theoretical models of ELS in the context of biomedical applications is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20935748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20935748"><span id="translatedtitle"><span class="hlt">Light</span> <span class="hlt">scattering</span> at oblique incidence on two coaxial cylinders.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yousif, H A; Mattis, R E; Kozminski, K</p> <p>1994-06-20</p> <p>A solution for the problem of a plane wave at oblique incidence on two coaxial cylinders is presented. The solution of the wave equation is determined for various geometric regions, and boundary conditions are applied at the material interfaces. The resulting solution consists of a system of eight equations in eight unknown coefficients. Expressions for two of the Mueller-<span class="hlt">scattering</span> matrix elements (S(11) and S(12)) and the extinction, <span class="hlt">scattering</span>, and backscattering cross sections are derived. A numerical algorithm for the solution is developed and implemented. The algorithm is tested for several limiting cases: homogeneous, hollow, and metal-core cylinders at various angles of incidence for TM and TE waves. Comparisons of the results of the algorithm with the results of studies reported in the literature are made. The comparisons are favorable, achieving good agreement with published work. For two coaxial cylinders, the numerical calculations show that if one is to use <span class="hlt">light</span> <span class="hlt">scattering</span> as a diagnostic tool, both of the Mueller-<span class="hlt">scattering</span> matrix elements S(11) and S(12) must be measured simultaneously. In addition, the backscattering cross section is very sensitive for monitoring change in the radii of the cylinders.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1133673','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1133673"><span id="translatedtitle">CIRCULAR INTENSITY DIFFERENTIAL <span class="hlt">SCATTERING</span> OF <span class="hlt">LIGHT</span> BY HELICAL STRUCTURES. III. A GENERAL POLARIZABILITY TENSOR AND ANOMALOUS <span class="hlt">SCATTERING</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bustamante, Carlos; Maestre, Marcos F.; Tinoco, Jr., Ignacio</p> <p>1980-11-01</p> <p>Numerical calculations of the circular intensity differential <span class="hlt">scattering</span> of <span class="hlt">light</span> by oriented helical structures made of units with general polarizability tensors are presented. The effects on the <span class="hlt">scattering</span> patterns of both absorptive and dispersive properties of the units are illustrated. The differential <span class="hlt">scattering</span> and the total <span class="hlt">scattering</span> both show anomalous <span class="hlt">scattering</span> phenomena; the differential <span class="hlt">scattering</span> pattern is asymmetric when the wavelength of incident <span class="hlt">light</span> is within an absorption band. Equations for bi-axial polarizabilities are used to derive the symmetry properties of the differential <span class="hlt">scattering</span> pattern and to show how this symmetry can be used to determine the right- or left-handed sense of the helical structure. The wavelength dependence of the <span class="hlt">scattering</span> pattern is obtained for a Lorentzian polarizability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JBO....15b0506P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JBO....15b0506P"><span id="translatedtitle">Static and dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> of healthy and malaria-parasite invaded red blood cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Yongkeun; Diez-Silva, Monica; Fu, Dan; Popescu, Gabriel; Choi, Wonshik; Barman, Ishan; Suresh, Subra; Feld, Michael S.</p> <p>2010-03-01</p> <p>We present the <span class="hlt">light</span> <span class="hlt">scattering</span> of individual Plasmodium falciparum-parasitized human red blood cells (Pf-RBCs), and demonstrate progressive alterations to the <span class="hlt">scattering</span> signal arising from the development of malaria-inducing parasites. By selectively imaging the electric fields using quantitative phase microscopy and a Fourier transform <span class="hlt">light</span> <span class="hlt">scattering</span> technique, we calculate the <span class="hlt">light</span> <span class="hlt">scattering</span> maps of individual Pf-RBCs. We show that the onset and progression of pathological states of the Pf-RBCs can be clearly identified by the static <span class="hlt">scattering</span> maps. Progressive changes to the biophysical properties of the Pf-RBC membrane are captured from dynamic <span class="hlt">light</span> <span class="hlt">scattering</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020050548','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020050548"><span id="translatedtitle">Assessing the <span class="hlt">Rayleigh</span> Intensity Remote Leak Detection Technique</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clements, Sandra</p> <p>2001-01-01</p> <p>Remote sensing technologies are being considered for efficient, low cost gas leak detection. An exploratory project to identify and evaluate remote sensing technologies for application to gas leak detection is underway. During Phase 1 of the project, completed last year, eleven specific techniques were identified for further study. One of these, the <span class="hlt">Rayleigh</span> Intensity technique, would make use of changes in the <span class="hlt">light</span> <span class="hlt">scattered</span> off of gas molecules to detect and locate a leak. During the 10-week Summer Faculty Fellowship Program, the <span class="hlt">scatter</span> of <span class="hlt">light</span> off of gas molecules was investigated. The influence of <span class="hlt">light</span> <span class="hlt">scattered</span> off of aerosols suspended in the atmosphere was also examined to determine if this would adversely affect leak detection. Results of this study indicate that in unconditioned air, it will be difficult, though perhaps not impossible, to distinguish between a gas leak and natural variations in the aerosol content of the air. Because information about the particle size distribution in clean room environments is incomplete, the applicability in clean rooms is uncertain though more promising than in unconditioned environments. It is suggested that problems caused by aerosols may be overcome by using the <span class="hlt">Rayleigh</span> Intensity technique in combination with another remote sensing technique, the <span class="hlt">Rayleigh</span> Doppler technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920055441&hterms=Experiment+Light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DExperiment%2BLight','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920055441&hterms=Experiment+Light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DExperiment%2BLight"><span id="translatedtitle">Stray-<span class="hlt">light</span> suppression with high-collection efficiency in laser <span class="hlt">light-scattering</span> experiments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deilamian, K.; Gillaspy, J. D.; Kelleher, D. E.</p> <p>1992-01-01</p> <p>An optical system is described for collecting a large fraction of fluorescent <span class="hlt">light</span> emitted isotropically from a cylindrical interaction region. While maintaining an overall detection efficiency of 9 percent, the system rejects, by more than 12 orders of magnitude, incident laser <span class="hlt">light</span> along a single axis that intersects the interaction region. Such a system is useful for a wide variety of <span class="hlt">light-scattering</span> experiments in which high-collection efficiency is desirable, but in which <span class="hlt">light</span> from an incident laser beam must be rejected without resorting to spectral filters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013A%26A...549A..91L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013A%26A...549A..91L"><span id="translatedtitle">Spectroscopy of diffuse <span class="hlt">light</span> in dust clouds. <span class="hlt">Scattered</span> <span class="hlt">light</span> and the solar neighbourhood radiation field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lehtinen, K.; Mattila, K.</p> <p>2013-01-01</p> <p>Context. The optical surface brightness of dark nebulae is mainly due to <span class="hlt">scattering</span> of integrated starlight by classical dust grains. It contains information on the impinging interstellar radiation field, cloud structure, and grain <span class="hlt">scattering</span> properties. We have obtained spectra of the <span class="hlt">scattered</span> <span class="hlt">light</span> from 3500 to 9000 Å in two globules, the Thumbprint Nebula and DC 303.8-14.2. Aims. We use observations of the <span class="hlt">scattered</span> <span class="hlt">light</span> to study the impinging integrated starlight spectrum as well as the <span class="hlt">scattered</span> Hα and other line emissions from all over the sky. We search also for the presence of other than <span class="hlt">scattered</span> <span class="hlt">light</span> in the two globules. Methods. We obtained long-slit spectra encompassing the whole globule plus adjacent sky in a one-slit setting, thus enabling efficient elimination of airglow and other foreground sky components. We calculated synthetic integrated starlight spectra for the solar neighbourhood using HIPPARCOS-based stellar distributions and the spectral library of Pickles. Results. Spectra are presented separately for the bright rims and dark cores of the globules. The continuum spectral energy distributions and absorption line spectra can be well modelled with the synthetic integrated starlight spectra. Emission lines of Hα +[N II], Hβ, and [S II] are detected and are interpreted in terms of <span class="hlt">scattered</span> <span class="hlt">light</span> plus an in situ warm ionized medium component behind the globules. We detected an excess of emission over the wavelength range 5200-8000 Å in DC 303.8-14.2 but the nature of this emission remains open. Based on observations collected at the European Southern Observatory, Chile, under programme ESO No. 073.C-0239(A). Appendix A is available in electronic form at http://www.aanda.org.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27152337','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27152337"><span id="translatedtitle">Cavity-enhanced coherent <span class="hlt">light</span> <span class="hlt">scattering</span> from a quantum dot.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bennett, Anthony J; Lee, James P; Ellis, David J P; Meany, Thomas; Murray, Eoin; Floether, Frederik F; Griffths, Jonathan P; Farrer, Ian; Ritchie, David A; Shields, Andrew J</p> <p>2016-04-01</p> <p>The generation of coherent and indistinguishable single photons is a critical step for photonic quantum technologies in information processing and metrology. A promising system is the resonant optical excitation of solid-state emitters embedded in wavelength-scale three-dimensional cavities. However, the challenge here is to reject the unwanted excitation to a level below the quantum signal. We demonstrate this using coherent photon <span class="hlt">scattering</span> from a quantum dot in a micropillar. The cavity is shown to enhance the fraction of <span class="hlt">light</span> that is resonantly <span class="hlt">scattered</span> toward unity, generating antibunched indistinguishable photons that are 16 times narrower than the time-bandwidth limit, even when the transition is near saturation. Finally, deterministic excitation is used to create two-photon N00N states with which we make superresolving phase measurements in a photonic circuit. PMID:27152337</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvD..94f3001C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvD..94f3001C"><span id="translatedtitle"><span class="hlt">Light</span> dark matter <span class="hlt">scattering</span> in outer neutron star crusts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cermeño, Marina; Pérez-García, M. Ángeles; Silk, Joseph</p> <p>2016-09-01</p> <p>We calculate for the first time the phonon excitation rate in the outer crust of a neutron star due to <span class="hlt">scattering</span> from <span class="hlt">light</span> dark matter (LDM) particles gravitationally boosted into the star. We consider dark matter particles in the sub-GeV mass range <span class="hlt">scattering</span> off a periodic array of nuclei through an effective scalar-vector interaction with nucleons. We find that LDM effects cause a modification of the net number of phonons in the lattice as compared to the standard thermal result. In addition, we estimate the contribution of LDM to the ion-ion thermal conductivity in the outer crust and find that it can be significantly enhanced at large densities. Our results imply that for magnetized neutron stars the LDM-enhanced global conductivity in the outer crust will tend to reduce the anisotropic heat conduction between perpendicular and parallel directions to the magnetic field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6367280','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6367280"><span id="translatedtitle">An introduction to dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> of macromolecules</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schmitz, K.S. )</p> <p>1990-01-01</p> <p>Dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS) techniques provide information about size, shape, and flexibility of particles as well as offering insight concerning the nature of the interactions between particles and their environments. This book offers a study of DLS by macromolecular and polyelectrolyte solutions. With an emphasis on the interpretation of DLS data, the material is organized according to the increasing complexity of the system, ranging from dilute solutions of noninteracting small particles to the more complex multicomponent systems of strongly interacting large particles. Because the dynamics of these systems can be complex, various methods used to analyze correlation functions of multidecay processes are discussed. Also covered are complementary techniques that assist in the interpretation of DLS data - such as neutron <span class="hlt">scattering</span> and spin echo.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27152337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27152337"><span id="translatedtitle">Cavity-enhanced coherent <span class="hlt">light</span> <span class="hlt">scattering</span> from a quantum dot.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bennett, Anthony J; Lee, James P; Ellis, David J P; Meany, Thomas; Murray, Eoin; Floether, Frederik F; Griffths, Jonathan P; Farrer, Ian; Ritchie, David A; Shields, Andrew J</p> <p>2016-04-01</p> <p>The generation of coherent and indistinguishable single photons is a critical step for photonic quantum technologies in information processing and metrology. A promising system is the resonant optical excitation of solid-state emitters embedded in wavelength-scale three-dimensional cavities. However, the challenge here is to reject the unwanted excitation to a level below the quantum signal. We demonstrate this using coherent photon <span class="hlt">scattering</span> from a quantum dot in a micropillar. The cavity is shown to enhance the fraction of <span class="hlt">light</span> that is resonantly <span class="hlt">scattered</span> toward unity, generating antibunched indistinguishable photons that are 16 times narrower than the time-bandwidth limit, even when the transition is near saturation. Finally, deterministic excitation is used to create two-photon N00N states with which we make superresolving phase measurements in a photonic circuit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4846434','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4846434"><span id="translatedtitle">Cavity-enhanced coherent <span class="hlt">light</span> <span class="hlt">scattering</span> from a quantum dot</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bennett, Anthony J.; Lee, James P.; Ellis, David J. P.; Meany, Thomas; Murray, Eoin; Floether, Frederik F.; Griffths, Jonathan P.; Farrer, Ian; Ritchie, David A.; Shields, Andrew J.</p> <p>2016-01-01</p> <p>The generation of coherent and indistinguishable single photons is a critical step for photonic quantum technologies in information processing and metrology. A promising system is the resonant optical excitation of solid-state emitters embedded in wavelength-scale three-dimensional cavities. However, the challenge here is to reject the unwanted excitation to a level below the quantum signal. We demonstrate this using coherent photon <span class="hlt">scattering</span> from a quantum dot in a micropillar. The cavity is shown to enhance the fraction of <span class="hlt">light</span> that is resonantly <span class="hlt">scattered</span> toward unity, generating antibunched indistinguishable photons that are 16 times narrower than the time-bandwidth limit, even when the transition is near saturation. Finally, deterministic excitation is used to create two-photon N00N states with which we make superresolving phase measurements in a photonic circuit. PMID:27152337</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27314500','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27314500"><span id="translatedtitle">A <span class="hlt">Light</span> <span class="hlt">Scattering</span> Layer for Internal <span class="hlt">Light</span> Extraction of Organic <span class="hlt">Light</span>-Emitting Diodes Based on Silver Nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Keunsoo; Shin, Jin-Wook; Park, Jun-Hwan; Lee, Jonghee; Joo, Chul Woong; Lee, Jeong-Ik; Cho, Doo-Hee; Lim, Jong Tae; Oh, Min-Cheol; Ju, Byeong-Kwon; Moon, Jaehyun</p> <p>2016-07-13</p> <p>We propose and fabricate a random <span class="hlt">light</span> <span class="hlt">scattering</span> layer for <span class="hlt">light</span> extraction in organic <span class="hlt">light</span>-emitting diodes (OLEDs) with silver nanodots, which were obtained by melting silver nanowires. The OLED with the <span class="hlt">light</span> <span class="hlt">scattering</span> layer as an internal <span class="hlt">light</span> extraction structure was enhanced by 49.1% for the integrated external quantum efficiency (EQE). When a wrinkle structure is simultaneously used for an external <span class="hlt">light</span> extraction structure, the total enhancement of the integrated EQE was 65.3%. The EQE is maximized to 65.3% at a current level of 2.0 mA/cm(2). By applying an internal <span class="hlt">light</span> <span class="hlt">scattering</span> layer and wrinkle structure to an OLED, the variance in the emission spectra was negligible over a broad viewing angle. Power mode analyses with finite difference time domain (FDTD) simulations revealed that the use of a <span class="hlt">scattering</span> layer effectively reduced the waveguiding mode while introducing non-negligible absorption. Our method offers an effective yet simple approach to achieve both efficiency enhancement and spectral stability for a wide range of OLED applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcSpA.167...19Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcSpA.167...19Y"><span id="translatedtitle">In-situ formation of ion-association nanoparticles induced enhancements of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> intensities for quantitative analysis of trace Hg2 + ions in environmental samples</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Qingling; Liu, Jian; Li, Banglin; Hu, Xiaoli; Liu, Shaopu; Chen, Gangcai</p> <p>2016-10-01</p> <p>In this paper, Hg2 + ions are demonstrated to form anionic [HgI4]2 - complexes after interacting with massive amount of I- ions. Subsequently, the addition of tetradecyl pyridyl bromide (TPB) can make [HgI4]2 - anionic complexes react with univalent tetradecyl pyridyl cationic ions (TP+), forming dispersed ion-association complexes (TP)2(HgI4). Due to the extrusion action of water and Van der Waals force, the hydrophobic ion-association complexes aggregate together, forming dispersed nanoparticles with an average size of about 8.5 nm. Meanwhile, resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) intensity is apparently enhanced due to the formation of (TP)2(HgI4) ion-association nanoparticles, contributing to a novel technique for Hg2 + detection. The wavelength of 365 nm is chosen as a detection wavelength and several conditions affecting the RRS responses of Hg2 + are optimized. Under the optimum condition, the developed method is used for the determination of Hg2 + in aqueous solution and the detection limit is estimated to be 0.8 ng mL- 1. Finally, the practical application of the developed method can be confirmed through the detections of Hg2 + in waste and river water samples with satisfactory results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27096866','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27096866"><span id="translatedtitle">Resonance <span class="hlt">Rayleigh</span> <span class="hlt">Scattering</span> Spectra of an Ion-Association Complex of Naphthol Green B-Chitosan System and Its Application in the Highly Sensitive Determination of Chitosan.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Weiai; Ma, Caijuan; Su, Zhengquan; Bai, Yan</p> <p>2016-04-01</p> <p>This work describes a highly-sensitive and accurate approach for the determination of chitosan (CTS) using Naphthol Green B (NGB) as a probe in the Resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) method. The interaction between CTS and NGB leads to notable enhancement of RRS, and the enhancement is proportional to the concentration of CTS over a certain range. Under optimum conditions, the calibration curve of ΔI against CTS concentration was ΔI = 1860.5c + 86.125 (c, µg/mL), R² = 0.9999, and the linear range and detection limit (DL) were 0.01-5.5 µg/mL and 8.87 ng/mL. Moreover, the effect of the molecular weight of CTS on the accurate quantification of CTS was studied. The experimental data were analyzed through linear regression analysis using SPSS20.0, and the molecular weight was found to have no statistical significance. This method has been applied to assay two CTS samples and obtained good recovery and reproducibility. PMID:27096866</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24957549','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24957549"><span id="translatedtitle">Synthesis of water-soluble Ag₂Se QDs as a novel resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> sensor for highly sensitive and selective ConA detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Shuguang; Zhang, Lichun; Tang, Yurong; Lv, Yi</p> <p>2014-09-01</p> <p>Ag2Se quantum dots (QDs) have attracted a lot of interest due to their potential applications in biosensing and bioimaging. A strategy is presented that involves coupling of selenium powder reduction with the binding of silver ions, and thioglycollic acid (TGA) and glycine as stabilizers to obtain ultrasmall Ag2Se QDs at 85 °C in aqueous solution. This strategy avoids high temperatures, high pressures and organic solvents so that water-soluble 3 nm Ag2Se QDs can be directly obtained. The conjugation of ConA to TGA stabilized Ag2Se QDs by hydrogen bonds leads to the adsorption of ConA to Ag2Se QDs and forms the aggregation and leads to the generation of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) as a readout signal for the sensing events. The reaction mechanism of Ag2Se QD RRS enhancement is studied in this work. The resulting RRS sensor enables the detection of ConA with limit of detection reaching 0.08 μg mL(-1) concentration in a wide linear range from 0.27 μg mL(-1) to 35 μg mL(-1). The recovery of spiked ConA in human serum samples ranges from 94% to 106%. The relative standard deviation (RSD) for eleven replicate detections is 3.6%. Our results correlate many important experimental observations and will fuel the further growth of this field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ExFl...39..375P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ExFl...39..375P"><span id="translatedtitle">Measurement of the conditioned turbulence and temperature field of a premixed Bunsen burner by planar laser <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> and stereo particle image velocimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pfadler, Sebastian; Löffler, Micha; Dinkelacker, Friedrich; Leipertz, Alfred</p> <p>2005-08-01</p> <p>The turbulence and temperature field of Bunsen-type turbulent lean methane/air flames has been investigated using planar laser <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (PLRS) and stereo particle image velocimetry (stereo PIV). Temporally averaged reaction progress variable plots have been computed from PLRS measurements in order to provide a basis with regards to the verification of computational fluid dynamics (CFD) models. Turbulence was characterised by stereo PIV in one plane for all three velocity components. Averaged velocity fields have been calculated, as well as Reynolds-decomposed fluctuation vector fields. Conditioned root mean square (RMS) values of the turbulent fluctuations in terms of unburnt and burnt gas could be determined by making use of the information gained from a threshold setting procedure in the PIV raw images. Furthermore, several length scales were measured indirectly from PIV vector plots. In this context, all integral length scales being accessible with stereo PIV were computed separately for the burnt and unburnt regions and were compared to each other. It could be observed that all integral length scales increased in the burnt zone. Additionally, the conditioned Taylor and Kolmogorov lengths have been extracted from the PIV field data, derived either from the zero-radius curvature of the correlation function or from common turbulence theory relations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24010452','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24010452"><span id="translatedtitle">Observation of <span class="hlt">Rayleigh</span> phonon <span class="hlt">scattering</span> through excitation of extremely high overtones in low-loss cryogenic acoustic cavities for hybrid quantum systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goryachev, Maxim; Creedon, Daniel L; Galliou, Serge; Tobar, Michael E</p> <p>2013-08-23</p> <p>The confinement of high frequency phonons approaching 1 GHz is demonstrated in phonon-trapping acoustic cavities at cryogenic temperatures using a low-coupled network approach. The frequency range is extended by nearly an order of magnitude, with excitation at greater than the 200th overtone achieved for the first time. Such a high frequency operation reveals <span class="hlt">Rayleigh</span>-type phonon <span class="hlt">scattering</span> losses due to highly diluted lattice impurities and corresponding glasslike behavior, with a maximum Q(L)×f product of 8.6×10(17) at 3.8 K and 4×10(17) at 15 mK. This suggests a limit on the Q×f product due to unavoidable crystal disorder. Operation at 15 mK is high enough in frequency that the average phonon occupation number is less than unity, with a loaded quality factor above half a billion. This work represents significant progress towards the utilization of such acoustic cavities for hybrid quantum systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AcSpA..69...71L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AcSpA..69...71L"><span id="translatedtitle">A novel method for study of the aggregation of protein induced by metal ion aluminum(III) using resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Long, Xiufen; Zhang, Caihua; Cheng, Jiongjia; Bi, Shuping</p> <p>2008-01-01</p> <p>We present a novel method for the study of the aggregation of protein induced by metal ion aluminum(III) using resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) technique. In neutral Tris-HCl medium, the effect of this aggregation of protein results in the enhancement of RRS intensity and the relationship between the enhancement of the RRS signal and the Al concentration is nonlinear. On this basis, we established a new method for the determination of the critical induced-aggregation concentrations ( CCIAC) of metal ion Al(III) inducing the protein aggregation. Our results show that many factors, such as, pH value, anions, salts, temperature and solvents have obvious effects. We also studied the extent of aggregation and structural changes using ultra-violet spectrometry, protein intrinsic fluorescence and circular dichroism to further understand the exact mechanisms of the aggregation characteristics of proteins induced by metal ion Al(III) at the molecular level, to help us to develop effective methods to investigate the toxicity of metal ion Al, and to provide theoretical and quantitative evidences for the development of appropriate treatments for neurodementia such as Parkinson's disease, Alzheimer's disease and dementia related to dialysis.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4849075','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4849075"><span id="translatedtitle">Resonance <span class="hlt">Rayleigh</span> <span class="hlt">Scattering</span> Spectra of an Ion-Association Complex of Naphthol Green B–Chitosan System and Its Application in the Highly Sensitive Determination of Chitosan</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Weiai; Ma, Caijuan; Su, Zhengquan; Bai, Yan</p> <p>2016-01-01</p> <p>This work describes a highly-sensitive and accurate approach for the determination of chitosan (CTS) using Naphthol Green B (NGB) as a probe in the Resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) method. The interaction between CTS and NGB leads to notable enhancement of RRS, and the enhancement is proportional to the concentration of CTS over a certain range. Under optimum conditions, the calibration curve of ΔI against CTS concentration was ΔI = 1860.5c + 86.125 (c, µg/mL), R2 = 0.9999, and the linear range and detection limit (DL) were 0.01–5.5 µg/mL and 8.87 ng/mL. Moreover, the effect of the molecular weight of CTS on the accurate quantification of CTS was studied. The experimental data were analyzed through linear regression analysis using SPSS20.0, and the molecular weight was found to have no statistical significance. This method has been applied to assay two CTS samples and obtained good recovery and reproducibility. PMID:27096866</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20939548','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20939548"><span id="translatedtitle">First hyperpolarizability of the natural aromatic amino acids tryptophan, tyrosine, and phenylalanine and the tripeptide lysine-tryptophan-lysine determined by hyper-<span class="hlt">Rayleigh</span> <span class="hlt">scattering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duboisset, J; Matar, G; Russier-Antoine, I; Benichou, E; Bachelier, G; Jonin, Ch; Ficheux, D; Besson, F; Brevet, P F</p> <p>2010-11-01</p> <p>We report the first hyperpolarizability of tryptophan (Trp) and tyrosine (Tyr) and an upper limit for that of phenylalanine (Phe), three natural aromatic amino acids. The measurements were performed with hyper-<span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> in an aqueous Tris buffer solution at a pH of 8.5 and 150 mM salt concentration with a fundamental wavelength of 780 nm. A value of (4.7 ± 0.7) × 10(-30) esu is found for Trp and (4.1 ± 0.7) × 10(-30) esu for Tyr whereas the upper limit of 1.4 × 10(-30) esu is found for that of Phe due to its limited solubility. The influence of the presence of lysine (Lys) in close vicinity of Trp is investigated with a measurement of the first hyperpolarizabilty of Trp in an excess of Lys and compared to the first hyperpolarizability obtained for the tripeptide Lys-Trp-Lys. The clear decrease of the values measured in these two cases indicates that the first hyperpolarizabilty of Trp is very sensitive to its local environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27235829','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27235829"><span id="translatedtitle">In-situ formation of ion-association nanoparticles induced enhancements of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> intensities for quantitative analysis of trace Hg(2+) ions in environmental samples.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Qingling; Liu, Jian; Li, Banglin; Hu, Xiaoli; Liu, Shaopu; Chen, Gangcai</p> <p>2016-10-01</p> <p>In this paper, Hg(2+) ions are demonstrated to form anionic [HgI4](2-) complexes after interacting with massive amount of I(-) ions. Subsequently, the addition of tetradecyl pyridyl bromide (TPB) can make [HgI4](2-) anionic complexes react with univalent tetradecyl pyridyl cationic ions (TP(+)), forming dispersed ion-association complexes (TP)2(HgI4). Due to the extrusion action of water and Van der Waals force, the hydrophobic ion-association complexes aggregate together, forming dispersed nanoparticles with an average size of about 8.5nm. Meanwhile, resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) intensity is apparently enhanced due to the formation of (TP)2(HgI4) ion-association nanoparticles, contributing to a novel technique for Hg(2+) detection. The wavelength of 365nm is chosen as a detection wavelength and several conditions affecting the RRS responses of Hg(2+) are optimized. Under the optimum condition, the developed method is used for the determination of Hg(2+) in aqueous solution and the detection limit is estimated to be 0.8ngmL(-1). Finally, the practical application of the developed method can be confirmed through the detections of Hg(2+) in waste and river water samples with satisfactory results. PMID:27235829</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcSpA.156...22L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcSpA.156...22L"><span id="translatedtitle">A simple and rapid method for direct determination of Al(III) based on the enhanced resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> of hemin-functionalized graphene-Al(III) system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ling, Yu; Chen, Ling Xiao; Dong, Jiang Xue; Li, Nian Bing; Luo, Hong Qun</p> <p>2016-03-01</p> <p>A novel method for direct determination of Al(III) by using hemin-functionalized graphene (H-GO) has been established based on the enhancement of resonance <span class="hlt">Rayleigh</span> <span class="hlt">scattering</span> (RRS) intensity. The characteristics of RRS spectra, the optimum reaction conditions, and the reaction mechanism have been investigated. In this experiment, the Al(III) would exist in sol-gel Al(OH)3 species under the condition of pH 5.9 in aqueous solutions. When H-GO existed in the solution, the sol-gel Al(OH)3 would react with H-GO and result in enhancement of RRS intensity, owing to the enhanced hydrophobicity of H-GO surface. Therefore, a simple and rapid sensor for Al(III) was developed. The increased intensity of RRS is directly proportional to the concentration of Al(III) in the range of 10 nM-6 μM, along with a detection limit of 0.87 nM. Moreover, the sensor has been applied to determination of Al(III) concentration in real water and aspirin tablet samples with satisfactory results. Therefore, the proposed method is promising as an effective means for selective and sensitive determination of Al(III).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15903604','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15903604"><span id="translatedtitle">Coherence of <span class="hlt">light</span> <span class="hlt">scattered</span> from a randomly rough surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leskova, T A; Maradudin, A A; Munõz-Lopez, J</p> <p>2005-03-01</p> <p>We study the coherence of p-polarized <span class="hlt">light</span> <span class="hlt">scattered</span> from a one-dimensional weakly rough random metal surface in contact with vacuum. The mutual coherence function of the single nonzero component of the <span class="hlt">scattered</span> magnetic field is calculated in planes parallel to, and at increasing distances from, the mean <span class="hlt">scattering</span> surface in the vacuum region. It is found to be the sum of a contribution that is independent of the distance from the mean surface and a contribution that is a function of this distance and decays to zero over a distance of the order of the wavelength of the incident <span class="hlt">light</span>. It is also shown that the spatial coherence of the electromagnetic field in the far field in a plane at a fixed distance from the mean surface, as a function of the relative distance along it, mimics the surface height autocorrelation function at short relative distances and oscillates with two periods, T(1) = lambda and T(2) = lambda/sin theta(0), where theta(0) is the angle of incidence. The former is due to the excitation of lateral waves, while the latter is due to the coherent interference of the multiple <span class="hlt">scattering</span> processes that lead to the enhanced backscattering effect. In the near field the spatial coherence of the electromagnetic field measured at a fixed distance from the mean surface displays oscillations that are due to the excitation of surface plasmon polaritons. The period of these oscillations equals the wavelength of the surface plasmon polaritons, while the exponential decay of their amplitude is determined by the energy mean free path of the surface plasmon polaritons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4244..552D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4244..552D"><span id="translatedtitle">Dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> in veterinary medicine: refinement of diagnostic criteria</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubin, Stephen; Zietz, Stanley; Gabriel, Karl L.; Gabriel, David; DellaVecchia, Michael A.; Ansari, Rafat R.</p> <p>2001-05-01</p> <p>In dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> (DLS), the structure or material of interest, suspended in a fluid, is illuminated by a beam of laser <span class="hlt">light</span> and the <span class="hlt">scattered</span> <span class="hlt">light</span> is interpreted in terms of diffusion coefficient, particle size or its distribution. DLS has shown clear promise as a non-invasive, objective and precise diagnostic modality for investigation of lens opacity (cataract) and other medical and toxicological problems. The clinical potential of LDS has been demonstrated in several species both in vivo and in vitro. In many clinical cases, discernment between normal and diseased patients is possible by simple inspection of the particle size distribution. However a more rigorous and sensitive classification scheme is needed, particularly for evaluation of therapy and estimation of tissue injury. The data supplied by DLS investigation is inherently multivariate and its most efficient interpretation requires a multivariate approach which includes the variability among specimens as well as any correlation among the variables (e.g. across the particle size distribution). We present a brief review of DLS methodology, illustrative data and our efforts toward a diagnostic classification scheme. In particular we will describe application of the Mahalanobis distance and related statistical methods to DLS data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RScI...86k5107Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RScI...86k5107Z"><span id="translatedtitle">Ultrafast image-based dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> for nanoparticle sizing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Wu; Zhang, Jie; Liu, Lili; Cai, Xiaoshu</p> <p>2015-11-01</p> <p>An ultrafast sizing method for nanoparticles is proposed, called as UIDLS (Ultrafast Image-based Dynamic <span class="hlt">Light</span> <span class="hlt">Scattering</span>). This method makes use of the intensity fluctuation of <span class="hlt">scattered</span> <span class="hlt">light</span> from nanoparticles in Brownian motion, which is similar to the conventional DLS method. The difference in the experimental system is that the <span class="hlt">scattered</span> <span class="hlt">light</span> by nanoparticles is received by an image sensor instead of a photomultiplier tube. A novel data processing algorithm is proposed to directly get correlation coefficient between two images at a certain time interval (from microseconds to milliseconds) by employing a two-dimensional image correlation algorithm. This coefficient has been proved to be a monotonic function of the particle diameter. Samples of standard latex particles (79/100/352/482/948 nm) were measured for validation of the proposed method. The measurement accuracy of higher than 90% was found with standard deviations less than 3%. A sample of nanosilver particle with nominal size of 20 ± 2 nm and a sample of polymethyl methacrylate emulsion with unknown size were also tested using UIDLS method. The measured results were 23.2 ± 3.0 nm and 246.1 ± 6.3 nm, respectively, which is substantially consistent with the transmission electron microscope results. Since the time for acquisition of two successive images has been reduced to less than 1 ms and the data processing time in about 10 ms, the total measuring time can be dramatically reduced from hundreds seconds to tens of milliseconds, which provides the potential for real-time and in situ nanoparticle sizing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22482618','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22482618"><span id="translatedtitle">Ultrafast image-based dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> for nanoparticle sizing</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhou, Wu; Zhang, Jie; Liu, Lili; Cai, Xiaoshu</p> <p>2015-11-15</p> <p>An ultrafast sizing method for nanoparticles is proposed, called as UIDLS (Ultrafast Image-based Dynamic <span class="hlt">Light</span> <span class="hlt">Scattering</span>). This method makes use of the intensity fluctuation of <span class="hlt">scattered</span> <span class="hlt">light</span> from nanoparticles in Brownian motion, which is similar to the conventional DLS method. The difference in the experimental system is that the <span class="hlt">scattered</span> <span class="hlt">light</span> by nanoparticles is received by an image sensor instead of a photomultiplier tube. A novel data processing algorithm is proposed to directly get correlation coefficient between two images at a certain time interval (from microseconds to milliseconds) by employing a two-dimensional image correlation algorithm. This coefficient has been proved to be a monotonic function of the particle diameter. Samples of standard latex particles (79/100/352/482/948 nm) were measured for validation of the proposed method. The measurement accuracy of higher than 90% was found with standard deviations less than 3%. A sample of nanosilver particle with nominal size of 20 ± 2 nm and a sample of polymethyl methacrylate emulsion with unknown size were also tested using UIDLS method. The measured results were 23.2 ± 3.0 nm and 246.1 ± 6.3 nm, respectively, which is substantially consistent with the transmission electron microscope results. Since the time for acquisition of two successive images has been reduced to less than 1 ms and the data processing time in about 10 ms, the total measuring time can be dramatically reduced from hundreds seconds to tens of milliseconds, which provides the potential for real-time and in situ nanoparticle sizing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26628172','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26628172"><span id="translatedtitle">Ultrafast image-based dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> for nanoparticle sizing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Wu; Zhang, Jie; Liu, Lili; Cai, Xiaoshu</p> <p>2015-11-01</p> <p>An ultrafast sizing method for nanoparticles is proposed, called as UIDLS (Ultrafast Image-based Dynamic <span class="hlt">Light</span> <span class="hlt">Scattering</span>). This method makes use of the intensity fluctuation of <span class="hlt">scattered</span> <span class="hlt">light</span> from nanoparticles in Brownian motion, which is similar to the conventional DLS method. The difference in the experimental system is that the <span class="hlt">scattered</span> <span class="hlt">light</span> by nanoparticles is received by an image sensor instead of a photomultiplier tube. A novel data processing algorithm is proposed to directly get correlation coefficient between two images at a certain time interval (from microseconds to milliseconds) by employing a two-dimensional image correlation algorithm. This coefficient has been proved to be a monotonic function of the particle diameter. Samples of standard latex particles (79/100/352/482/948 nm) were measured for validation of the proposed method. The measurement accuracy of higher than 90% was found with standard deviations less than 3%. A sample of nanosilver particle with nominal size of 20 ± 2 nm and a sample of polymethyl methacrylate emulsion with unknown size were also tested using UIDLS method. The measured results were 23.2 ± 3.0 nm and 246.1 ± 6.3 nm, respectively, which is substantially consistent with the transmission electron microscope results. Since the time for acquisition of two successive images has been reduced to less than 1 ms and the data processing time in about 10 ms, the total measuring time can be dramatically reduced from hundreds seconds to tens of milliseconds, which provides the potential for real-time and in situ nanoparticle sizing. PMID:26628172</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5630...66L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5630...66L"><span id="translatedtitle">Changes in hemodynamics and <span class="hlt">light</span> <span class="hlt">scattering</span> during cortical spreading depression</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Pengcheng; Yang, Yuanyuan; Luo, Qingming</p> <p>2005-01-01</p> <p>Cortical spreading depression (CSD) has been known to play an important role in the mechanism of migraine, stroke and brain injure. Optical imaging of intrinsic signals has been shown a powerful method for characterizing the spatial and temporal pattern of the propagation of CSD. However, the possible physiological mechanisms underlying the intrinsic optical signal (IOS) during CSD still remain incompletely understood. In this study, a spectroscopic recording of the change in optical intrinsic signal during CSD was performed and an analysis method based on the modified Beer-Lambert law was used to estimate the changes in the concentration of HbO2 and Hb, and changes in <span class="hlt">light</span> <span class="hlt">scattering</span> from the spectra data. The CSD were induced by pinprick in 10 α-chloralose/urethane anesthetized Sprague-Dawley rats. In all experiments, four-phasic changes in optical reflectance were observed at 450 nm ~ 570 nm, and triphasic changes in optical reflectance were observed in the range of 570 nm ~750 nm. But at 750 nm ~ 850 nm, only biphasic changes of optical signal were detected. Converting the spectra data to the changes in <span class="hlt">light</span> <span class="hlt">scattering</span> and concentration of Hb and HbO2, we found that the CSD induced an initial increase in concentration of HbO2 (amplitude: 9.0+/-3.7%), which was 26.2+/-18.6 s earlier than the onset of increase of Hb concentration. Furthermore, the concentration of HbO2 showed a four-phasic change, whereas the concentration of Hb only showed a biphasic change. For the changes in <span class="hlt">light</span> <span class="hlt">scattering</span> during CSD, a triphasic change was observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4353..106B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4353..106B"><span id="translatedtitle"><span class="hlt">Light</span>-induced <span class="hlt">scattering</span> in laser radiation nonlinear optical limiting based on fullerene-containing media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belousova, Inna M.; Grigor'ev, Vladimir A.; Danilov, Oleg B.; Kalintsev, Alexander G.; Kris'ko, A. V.; Mironova, N. G.; Yur'ev, Michail S.</p> <p>2001-03-01</p> <p>The contribution of <span class="hlt">light</span> induced <span class="hlt">scattering</span> to nonlinear optical limiting is theoretically and experimentally investigated. It is shown that <span class="hlt">light</span> induced <span class="hlt">scattering</span> is caused by fine-scale (1 divided by 10 micrometer) inhomogeneities formation, very low (comparable to spontaneous noise) laser beam inhomogeneities can evolve into <span class="hlt">light</span> induced <span class="hlt">scattering</span>. The numerical modeling of <span class="hlt">scattered</span> radiation angular distribution and laser radiation attenuation in optical limiters was performed. The modeling results were compared with the experimental ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19189014','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19189014"><span id="translatedtitle">Multiple <span class="hlt">scattering</span> of <span class="hlt">light</span> in three-dimensional photonic quasicrystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ledermann, Alexandra; Wiersma, Diederik S; Wegener, Martin; von Freymann, Georg</p> <p>2009-02-01</p> <p>Recent experiments on three-dimensional icosahedral dielectric photonic quasicrystals have shown several unexpected features: transmitted femtosecond pulses developed a trailing "diffusive" exponential tail and the sum of (zeroth-order) transmittance and reflectance was well below unity. These experimental findings have previously been ascribed to sample imperfections. Here, we analyze these findings by using 3D periodic approximants of the ideal photonic quasicrystals. We show that the experimental observations can be explained in terms of multiple <span class="hlt">scattering</span> of <span class="hlt">light</span> within these structures, i.e., in terms of intrinsic rather than purely extrinsic quasicrystal properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7306E..1BD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7306E..1BD"><span id="translatedtitle">Polarized <span class="hlt">light</span> <span class="hlt">scattering</span> technique for morphological characterization of waterborne pathogens</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Devarakonda, Venkat V.; Manickavasagam, Sivakumar</p> <p>2009-05-01</p> <p>We have recently developed an elliptically polarized <span class="hlt">light</span> <span class="hlt">scattering</span> (EPLS) technique to characterize the morphology of fine particles suspended in an optically non-absorbing medium such as water. This technique provides the size distribution, shape and agglomeration characteristics of suspended particles. This technique can be used to detect various types of biological pathogens such as bacteria, protozoa and viruses in potable water systems. Here we report results obtained from EPLS measurements on two strains of Bacillus spores suspended in water along with comparison with electron microscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JBO....16g0505F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JBO....16g0505F"><span id="translatedtitle">Detecting apoptosis using dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> with optical coherence tomography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farhat, Golnaz; Mariampillai, Adrian; Yang, Victor X. D.; Czarnota, Gregory J.; Kolios, Michael C.</p> <p>2011-07-01</p> <p>A dynamic <span class="hlt">light</span> <span class="hlt">scattering</span> technique is implemented using optical coherence tomography (OCT) to measure the change in intracellular motion as cells undergo apoptosis. Acute myeloid leukemia cells were treated with cisplatin and imaged at a frame rate of 166 Hz using a 1300 nm swept-source OCT system at various times over a period of 48 h. Time correlation analysis of the speckle intensities indicated a significant increase in intracellular motion 24 h after treatment. This rise in intracellular motion correlated with histological findings of irregularly shaped and fragmented cells indicative of cell membrane blebbing and fragmentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JQSRT.178....5K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JQSRT.178....5K"><span id="translatedtitle">Peregrinations through topics in <span class="hlt">light</span> <span class="hlt">scattering</span> and radiative transfer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kattawar, George W.</p> <p>2016-07-01</p> <p>In this van de Hulst essay, I have taken the liberty to present a journey through some topics in <span class="hlt">light</span> <span class="hlt">scattering</span> and radiative transfer which I feel were major contributions to the field but the number of topics I would like to cover is far more numerous than I have the time or the space to present. I also wanted to share with the reader some heartwarming memories I have of my wonderful friend and truly distinguished colleague Hendrik Christoffel van de Hulst (affectionately known to his colleagues as "Henk") whom I consider to be one of the preeminent scientists of his era.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21470686','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21470686"><span id="translatedtitle">Peculiarities of excitation of surface plasmons upon noncollinear <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Andreev, Anatolii V; Korneev, A A; Mukina, L S; Nazarov, Maksim M; Prudnikov, I R; Shkurinov, A P</p> <p>2005-01-31</p> <p>The efficiency of excitation of surface plasmons upon noncollinear <span class="hlt">light</span> <span class="hlt">scattering</span> from a metal diffraction grating is studied. It is shown that this efficiency strongly depends on the grating profile and the azimuthal angle of rotation. The relation between the spatial configuration of the electromagnetic field near the grating-vacuum interface and the possibility of excitation of plasmons is found. Taking into account different conditions for plasmon excitation, the peculiarities of experimental angular dependences of specular reflection are explained. (interaction of laser radiation with matter. laser plasma)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JChPh.137k4509C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.137k4509C"><span id="translatedtitle">Hydration properties of small hydrophobic molecules by Brillouin <span class="hlt">light</span> <span class="hlt">scattering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comez, L.; Lupi, L.; Paolantoni, M.; Picchiò, F.; Fioretto, D.</p> <p>2012-09-01</p> <p>We study the relaxation of water molecules next to hydrophobic solutes with different functional groups by Brillouin <span class="hlt">light</span> <span class="hlt">scattering</span>. Evidence is given for (i) water activation energy in trimethylamine-N-oxide, proline and t-butyl alcohol diluted solutions which is comparable to that of neat water, almost independent from solute mole fraction and (ii) moderate slowdown of relaxation time of proximal water compared to the bulk, which is consistent with excluded volume models. Assuming that the main contribution to viscosity comes from bulk and hydration water, a rationale is given of the phenomenological Arrhenius' laws for the viscosity of diluted aqueous solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22365564','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22365564"><span id="translatedtitle">HD100546 multi-epoch <span class="hlt">scattered</span> <span class="hlt">light</span> observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Avenhaus, Henning; Quanz, Sascha P.; Meyer, Michael R.; Brittain, Sean D.; Carr, John S.; Najita, Joan R.</p> <p>2014-07-20</p> <p>We present H, K{sub s}, and L' filter polarimetric differential imaging (PDI) data for the transitional disk around HD100546 obtained in 2013, together with an improved re-reduction of previously published 2006 data. We reveal the disk in polarized <span class="hlt">scattered</span> <span class="hlt">light</span> in all three filters, achieving an inner working angle of ∼0.''1. Additional, short-exposure observations in the H and K{sub s} filters probe the surroundings of the star down to ∼0.''03 (∼3 AU). HD100546 is fascinating because of its variety of sub-structures possibly related to forming planets in the disk, and PDI is currently the best technique for imaging them in the near-IR. For the first time ever, we detect a disk in L-band PDI data, and we constrain the outer radius of the inner hole to 14 ± 2 AU and its eccentricity to <0.133. A dark lane is detected between ∼0.''2-0.''6 AU in the front side of the disk, which is likely an effect of the <span class="hlt">scattering</span> angle and the <span class="hlt">scattering</span> function of the grains. We find a spiral arm in the northeast that has no obvious connection to spiral arms seen before by other authors further out in the disk, but winds are in the same direction (clockwise). The two bright <span class="hlt">scattering</span> peaks along the semi-major axis are asymmetric, with the southeastern one being significantly brighter. This could be related to the inner companion candidate that is close to the brighter side of the disk at the time of the observations. The <span class="hlt">scattering</span> color is close to gray between the H and K{sub s} filters ([H]–[K{sub s}] = 0.19 ± 0.11), but the <span class="hlt">scattering</span> in the L' filter is significantly weaker ([H]–[L'] = –1.08 ± 0.35, [K{sub s}]–[L'] = –1.27 ± 0.35). We measure the position angle of the disk to be 138° ± 3°, consistent with previous observations, and we derive the dust <span class="hlt">scattering</span> function in the H and K{sub s} filters between ∼35° and ∼130° at two different radii (30-50 and 80-110 AU) and show that our results are consistent with a disk that is more strongly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24979635','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24979635"><span id="translatedtitle">Coherence effects in <span class="hlt">scattering</span> order expansion of <span class="hlt">light</span> by atomic clouds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rouabah, Mohamed-Taha; Samoylova, Marina; Bachelard, Romain; Courteille, Philippe W; Kaiser, Robin; Piovella, Nicola</p> <p>2014-05-01</p> <p>We interpret cooperative <span class="hlt">scattering</span> by a collection of cold atoms as a multiple-<span class="hlt">scattering</span> process. Starting from microscopic equations describing the response of N atoms to a probe <span class="hlt">light</span> beam, we represent the total <span class="hlt">scattered</span> field as an infinite series of multiple-<span class="hlt">scattering</span> events. As an application of the method, we obtain analytical expressions of the coherent intensity in the double-<span class="hlt">scattering</span> approximation for Gaussian density profiles. In particular, we quantify the contributions of coherent backward and forward <span class="hlt">scattering</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvL.110u0401D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvL.110u0401D"><span id="translatedtitle"><span class="hlt">Light</span>-Wave Mixing and <span class="hlt">Scattering</span> with Quantum Gases</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deng, L.; Zhu, Chengjie; Hagley, E. W.</p> <p>2013-05-01</p> <p>We present a semiclassical theoretical framework on <span class="hlt">light</span>-wave mixing and <span class="hlt">scattering</span> with single-component quantum gases. We show that these optical processes originating from elementary excitations with dominant collective atomic recoil motion are stimulated Raman or hyper-Raman in nature. In the forward direction the wave-mixing process, which is the most efficient process in normal gases, is strongly reduced by the condensate structure factor even though the Bogoliubov dispersion relation automatically compensates the optical-wave phase mismatch. In the backward direction, however, the free-particle-like condensate structure factor and Bogoliubov dispersion result in highly efficient <span class="hlt">light</span>-wave mixing and collective atomic recoil motion that are enhanced by a stimulated hyper-Raman gain and a very narrow two-photon motional state resonance.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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