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Journal articles on the topic 'Polychromatic filters'

Author: Grafiati
Published: 4 June 2021
Last updated: 16 February 2022

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1

Kanzari, M., A. Bouzidi, and B. Rezig. "Interferential polychromatic filters." European Physical Journal B - Condensed Matter 36, no. 4 (December 1, 2003): 431–43. http://dx.doi.org/10.1140/epjb/e2004-00001-9.

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2

Hrdina, Radim, Igor Čepčiansky, and Hana Bittová. "Determination of the intensity of polychromatic radiation in the reaction compartment as a function of wavenumber." Collection of Czechoslovak Chemical Communications 56, no. 6 (1991): 1173–79. http://dx.doi.org/10.1135/cccc19911173.

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A procedure is suggested for studying the kinetics of photochemical reactions using excitation with polychromatic radiation, where the wavenumber dependence of the intensity of the polychromatic radiation entering the reaction compartment must be known. The observed relative intensities of the polychromatic source are calibrated by ferrioxalate actinometry, selected parts of the emission spectrum being eliminated by insertion of filters. The relative intensities of an HBO 200 high-pressure mercury lamp were measured. For the sake of brevity, the experimental data were fitted by a mathematical model (a polynominal), and only the parameters of the polynomial are presented in a tabular form.
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3

Cronin, Thomas W., Michael J. Bok, N. Justin Marshall, and Roy L. Caldwell. "Filtering and polychromatic vision in mantis shrimps: themes in visible and ultraviolet vision." Philosophical Transactions of the Royal Society B: Biological Sciences 369, no. 1636 (February 19, 2014): 20130032. http://dx.doi.org/10.1098/rstb.2013.0032.

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Stomatopod crustaceans have the most complex and diverse assortment of retinal photoreceptors of any animals, with 16 functional classes. The receptor classes are subdivided into sets responsible for ultraviolet vision, spatial vision, colour vision and polarization vision. Many of these receptor classes are spectrally tuned by filtering pigments located in photoreceptors or overlying optical elements. At visible wavelengths, carotenoproteins or similar substances are packed into vesicles used either as serial, intrarhabdomal filters or lateral filters. A single retina may contain a diversity of these filtering pigments paired with specific photoreceptors, and the pigments used vary between and within species both taxonomically and ecologically. Ultraviolet-filtering pigments in the crystalline cones serve to tune ultraviolet vision in these animals as well, and some ultraviolet receptors themselves act as birefringent filters to enable circular polarization vision. Stomatopods have reached an evolutionary extreme in their use of filter mechanisms to tune photoreception to habitat and behaviour, allowing them to extend the spectral range of their vision both deeper into the ultraviolet and further into the red.
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4

Yzuel, Mariá J., Juan C. Escalera, and Juan Campos. "Polychromatic axial behavior of axial apodizing and hyperresolving filters." Applied Optics 29, no. 11 (April 10, 1990): 1631. http://dx.doi.org/10.1364/ao.29.001631.

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5

Spring, K. R. "Multispectral Imaging in Light Microscopy." Microscopy and Microanalysis 4, S2 (July 1998): 126–27. http://dx.doi.org/10.1017/s1431927600020754.

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Many recent applications in light microscopy involve the use of multiple fluorophores or the delineation of signals arising from spectrally distinct sources. In microspectroscopy, it is always desirable to illuminate fluorescently-labeled microscopic specimens with monochromatic light as the narrowest possible excitation wavelength range usually results in the highest emission signal-to-noise ratio. Generation of polychromatic light from an arc lamp and selection of the excitation wavelength by interference filters or monochrometers are the most common techniques for excitation microspectrofluorometry. Emission spectroscopy is usually done with filter wheels, monochrometers, or interferometers inserted between the microscope detection port and the detector. This presentation will be directed toward other, less frequently-used, approaches for spectral scanning of the specimen in the light microscope. Three topics will be considered: 1) the use of acousto-optical tunable filters and lasers for rapid, narrow-band, excitation wavelength selection; 2) the use of holographic notch filters for rejection of unwanted excitation laser light; 3) using liquid-crystal tunable filters for emission scanning.
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6

Sara, Ira Devi, Thomas R. Betts, and Ralph Gottschalg. "Determining spectral response of a photovoltaic device using polychromatic filters." IET Renewable Power Generation 8, no. 5 (July 2014): 467–73. http://dx.doi.org/10.1049/iet-rpg.2013.0248.

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7

Soltani, Osswa, Jihene Zaghdoudi, and Mounir Kanzari. "High quality factor polychromatic filters based on hybrid photonic structures." Chinese Journal of Physics 56, no. 5 (October 2018): 2479–87. http://dx.doi.org/10.1016/j.cjph.2018.05.025.

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8

Truchaud, A. "Control of optics in random access analysers." Journal of Automatic Chemistry 10, no. 4 (1988): 175–78. http://dx.doi.org/10.1155/s1463924688000367.

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The technology behind random access analysers involves flexible optical systems which can measure absorbances for one reaction at different scheduled times, and for several reactions performed simultaneously at different wavelengths. Optics control involves light sources (continuous and flash mode), indexing of monochromatic filters, injection-moulded plastic cuvettes, optical fibres, and polychromatic analysis.
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9

Garcia, J., C. Ferreira, J. Campos, S. Bosch, M. S. Millán, and M. J. Yzuel. "Multichannel rotation-invariant pattern recognition for polychromatic objects using circular harmonic filters." Optics Communications 91, no. 5-6 (August 1992): 425–32. http://dx.doi.org/10.1016/0030-4018(92)90370-7.

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10

Soltani, Osswa, Sebastien Francoeur, Zina Baraket, and Mounir Kanzari. "Tunable polychromatic filters based on semiconductor-superconductor-dielectric periodic and quasi-periodic hybrid photonic crystal." Optical Materials 111 (January 2021): 110690. http://dx.doi.org/10.1016/j.optmat.2020.110690.

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11

Yzuel, M. J., J. C. Escalera, and J. Campos. "Three-dimensional Differences in the Polychromatic Responses of Non-uniform Transmission Filters and Equivalent Pupils." Journal of Modern Optics 36, no. 10 (October 1989): 1341–51. http://dx.doi.org/10.1080/09500348914551381.

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12

Escalera, Juan C., María J. Yzuel, and Juan Campos. "Control of the polychromatic response of an optical system through the use of annular color filters." Applied Optics 34, no. 10 (April 1, 1995): 1655. http://dx.doi.org/10.1364/ao.34.001655.

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13

Stevenson, Andrew W., and Francesca Di Lillo. "Estimating the absolute flux distribution for a synchrotron X-ray beam using ionization-chamber measurements with various filters." Journal of Synchrotron Radiation 24, no. 5 (August 11, 2017): 939–53. http://dx.doi.org/10.1107/s1600577517009274.

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It is shown that an extensive set of accurate ionization-chamber measurements with a primary polychromatic synchrotron X-ray beam transmitted through various filter combinations/thicknesses can be used to quite effectively estimate the absolute flux distribution. The basic technique is simple but the `inversion' of the raw data to extract the flux distribution is a fundamentally ill-posed problem. It is demonstrated, using data collected at the Imaging and Medical Beamline (IMBL) of the Australian Synchrotron, that the absolute flux can be quickly and reliably estimated if a suitable choice of filters is made. Results are presented as a function of the magnetic field (from 1.40 to 4.00 T) of the superconducting multi-pole wiggler insertion device installed at IMBL. A non-linear least-squares refinement of the data is used to estimate the incident flux distribution and then comparison is made with calculations from the programsSPECTRA,XOPandspec.exe. The technique described is important not only in estimating flux itself but also for a variety of other, derived, X-ray properties such as beam quality, power density and absorbed-dose rate. The applicability of the technique with a monochromatic X-ray beam for which there is significant harmonic contamination is also demonstrated. Whilst absolute results can also be derived in this monochromatic beam case, relative (integrated) flux values are sufficient for our primary aim of establishing reliable determinations of the percentages of the various harmonic components.
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14

Marshak, Alexander, Jay Herman, Szabo Adam, Blank Karin, Simon Carn, Alexander Cede, Igor Geogdzhayev, et al. "Earth Observations from DSCOVR EPIC Instrument." Bulletin of the American Meteorological Society 99, no. 9 (September 2018): 1829–50. http://dx.doi.org/10.1175/bams-d-17-0223.1.

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AbstractThe National Oceanic and Atmospheric Administration (NOAA) Deep Space Climate Observatory (DSCOVR) spacecraft was launched on 11 February 2015 and in June 2015 achieved its orbit at the first Lagrange point (L1), 1.5 million km from Earth toward the sun. There are two National Aeronautics and Space Administration (NASA) Earth-observing instruments on board: the Earth Polychromatic Imaging Camera (EPIC) and the National Institute of Standards and Technology Advanced Radiometer (NISTAR). The purpose of this paper is to describe various capabilities of the DSCOVR EPIC instrument. EPIC views the entire sunlit Earth from sunrise to sunset at the backscattering direction (scattering angles between 168.5° and 175.5°) with 10 narrowband filters: 317, 325, 340, 388, 443, 552, 680, 688, 764, and 779 nm. We discuss a number of preprocessing steps necessary for EPIC calibration including the geolocation algorithm and the radiometric calibration for each wavelength channel in terms of EPIC counts per second for conversion to reflectance units. The principal EPIC products are total ozone (O3) amount, scene reflectivity, erythemal irradiance, ultraviolet (UV) aerosol properties, sulfur dioxide (SO2) for volcanic eruptions, surface spectral reflectance, vegetation properties, and cloud products including cloud height. Finally, we describe the observation of horizontally oriented ice crystals in clouds and the unexpected use of the O2 B-band absorption for vegetation properties.
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15

Stevenson, Andrew W., Jeffrey C. Crosbie, Christopher J. Hall, Daniel Häusermann, Jayde Livingstone, and Jessica E. Lye. "Quantitative characterization of the X-ray beam at the Australian Synchrotron Imaging and Medical Beamline (IMBL)." Journal of Synchrotron Radiation 24, no. 1 (January 1, 2017): 110–41. http://dx.doi.org/10.1107/s1600577516015563.

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A critical early phase for any synchrotron beamline involves detailed testing, characterization and commissioning; this is especially true of a beamline as ambitious and complex as the Imaging & Medical Beamline (IMBL) at the Australian Synchrotron. IMBL staff and expert users have been performing precise experiments aimed at quantitative characterization of the primary polychromatic and monochromatic X-ray beams, with particular emphasis placed on the wiggler insertion devices (IDs), the primary-slit system and any in vacuo and ex vacuo filters. The findings from these studies will be described herein. These results will benefit IMBL and other users in the future, especially those for whom detailed knowledge of the X-ray beam spectrum (or `quality') and flux density is important. This information is critical for radiotherapy and radiobiology users, who ultimately need to know (to better than 5%) what X-ray dose or dose rate is being delivered to their samples. Various correction factors associated with ionization-chamber (IC) dosimetry have been accounted for, e.g. ion recombination, electron-loss effects. A new and innovative approach has been developed in this regard, which can provide confirmation of key parameter values such as the magnetic field in the wiggler and the effective thickness of key filters. IMBL commenced operation in December 2008 with an Advanced Photon Source (APS) wiggler as the (interim) ID. A superconducting multi-pole wiggler was installed and operational in January 2013. Results are obtained for both of these IDs and useful comparisons are made. A comprehensive model of the IMBL has been developed, embodied in a new computer program named spec.exe, which has been validated against a variety of experimental measurements. Having demonstrated the reliability and robustness of the model, it is then possible to use it in a practical and predictive manner. It is hoped that spec.exe will prove to be a useful resource for synchrotron science in general, and for hard X-ray beamlines, whether they are based on bending magnets or insertion devices, in particular. In due course, it is planned to make spec.exe freely available to other synchrotron scientists.
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16

Gahr, A., L. Weil, and R. Nie&sBligner. "Polychromatic actinometry with filter solutions." Water Research 29, no. 9 (September 1995): 2125–37. http://dx.doi.org/10.1016/0043-1354(94)00332-2.

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17

Oh, Seungtae, and Jiyoung Park. "Polychromator filter design with genetic algorithm." Measurement Science and Technology 26, no. 2 (December 17, 2014): 025201. http://dx.doi.org/10.1088/0957-0233/26/2/025201.

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18

Yappert, M. Cecilia, and J. D. Ingle. "Correction of Polychromatic Luminescence Signals for Inner-Filter Effects." Applied Spectroscopy 43, no. 5 (July 1989): 759–67. http://dx.doi.org/10.1366/0003702894202120.

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Fluorescence (FL) and absorbance (ABS) data are acquired simultaneously with a multiple detector spectrometer. The measured ABS is utilized in mathematical equations for automatic correction of fluorescence signals for attenuation (inner-filter effects) caused by significant absorption of the excitation or emission radiation by the fluorophore or other species. Correction equations are presented which apply to situations in which the excitation or emission beam cannot be considered monochromatic, for collection geometries involving optical fibers, and for chemiluminescence measurements. The correction scheme was tested with quinine sulfate (QS) as the analyte in the absence and presence of other chromophores (gentisic acid and methyl red). Even when conditions are such that the FL signal is attenuated by a factor of 5, the correction scheme is accurate to 2% or better. These corrections extend the linear range of the QS calibration curve by a factor of over 100, and they can improve the accuracy up to a factor of ten in cases for which polychromatic effects are important.
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19

Huang, K. D., Ding Hua Zhang, Fang Long Zha, and M. J. Li. "Integrated Method of Enhancing Image Quality for FPD-Based Cone-Beam Computed Tomography." Key Engineering Materials 474-476 (April 2011): 1277–82. http://dx.doi.org/10.4028/www.scientific.net/kem.474-476.1277.

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The main factors of impacting Cone-Beam Computed Tomography (CBCT) image quality and their causes were studied, and an integrated method of enhancing CBCT image quality was proposed according to the Digital Radiography (DR) imaging model. First, the original polychromatic X-ray was filtered into quasi-monochromatic X-ray by the filter plate of copper-tungsten alloy, in order to improve the quality of the original projection images. Then, the integrated artifact corrections for projection images were processed on the order of dark field correction, gain non-uniformity correction, scatter correction and beam hardening correction, to avoid the one-sidedness of only correcting a certain kind of artifact. Experimental results show that the method can almost eliminate the main artifacts of CBCT system and improve image clarity and signal to noise ratio.
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20

Kurskiev, G. S., Al P. Chernakov, V. A. Solovey, S. Yu Tolstyakov, E. E. Mukhin, A. N. Koval, A. N. Bazhenov, et al. "Digital filter polychromator for Thomson scattering applications." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 963 (May 2020): 163734. http://dx.doi.org/10.1016/j.nima.2020.163734.

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21

Solokha, V., G. Kurskiev, E. Mukhin, S. Tolstyakov, N. Babinov, A. Bazhenov, I. Bukreev, et al. "Digital filter polychromator for Thomson scattering applications." Journal of Physics: Conference Series 982 (February 2018): 012003. http://dx.doi.org/10.1088/1742-6596/982/1/012003.

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22

Ben Ali, Naim, Vigneswaran Dhasarathan, Haitham Alsaif, Youssef Trabelsi, Truong Khang Nguyen, Y. Bouazzi, and Mounir Kanzari. "Design of output-graded narrow polychromatic filter by using photonic quasicrystals." Physica B: Condensed Matter 582 (April 2020): 411918. http://dx.doi.org/10.1016/j.physb.2019.411918.

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23

Kusminarto and Umi Pratiwi. "Celluloide Film Based Infrared Bandpass Filter for Thermography." Advanced Materials Research 896 (February 2014): 668–71. http://dx.doi.org/10.4028/www.scientific.net/amr.896.668.

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A commercial digital camera was employed for thermal imaging. To do so, an infrared filter was required to block the light except the infrared part of it. The filter was developed using a celluloide colour film burned by certaint intensity of light. In this reseach intensity of monochromatics as well as polychromatics light of 1.00, 1.50, 2.70, 4.00, 8.00, 12.00, 16.00, 24.00, 30.0 and 40.00 klux have been used. The infrared filter produced then characterised their light transmitance using a spectrophotometer. Images of a light bulb and a hot iron plate were taken in a dark room using a digital camera equiped with and without infrared filter. The results show that the infrared filter produced from a celluloide colour film burned by a monochromatics light at intensity of 1.00 klux has the best permomance.
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24

Турьянский, А. Г., С. С. Гижа, and В. М. Сенков. "Широкополосная фильтрация рентгеновского спектра при прохождении через поликапиллярную структуру." Письма в журнал технической физики 45, no. 1 (2019): 23. http://dx.doi.org/10.21883/pjtf.2019.01.47151.17498r.

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AbstractThe efficiency of broadband filtering of a polychromatic X-ray spectrum by a polycapillary structure in the region of photon energies E > 10 keV was demonstrated. A polycapillary 40.5-mm-long rod made of borosilicate glass and containing 10^6 parallel hexagonal capillaries was used as a filter. Filtering was performed by introducing a misalignment of 0–4 mrad between the axis of this capillary structure and the primary beam direction. The relative attenuation of spectral density observed at energies ranging from 12 to 23 keV was as high as 17 dB.
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25

Kim, Munsok, Harry Owen, and Paul R. Carey. "High-Performance Raman Spectroscopic System Based on a Single Spectrograph, CCD, Notch Filters, and a Kr+ Laser Ranging from the Near-IR to Near-UV Regions." Applied Spectroscopy 47, no. 11 (November 1993): 1780–83. http://dx.doi.org/10.1366/0003702934066145.

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We describe the performance of a high-throughput system for detecting Raman spectra excited in the range from 320 to 750 nm. The system utilizes notch filters to reject Rayleigh scattering, a single polychromator as the dispersive element, and photon detection via a charge-coupled device. The filters, mirrors, and grating are changed to maximize performance in each excitation region. The excitation source consists of a Kr+ ion laser. Good-quality Raman data are reported for rhodamine 6G at 0.1 mM in methanol with the use of 752.5-nm excitation, and 0.2 mM flavin adenine dinucleotide (FAD) in tris buffer with the use of 647.1-nm excitation. High-quality resonance Raman data for 0.1 mM N-acetyl-glycine ethyl dithio ester in 5% CH3CN/H2O are also reported with the use of 324.0-nm excitation.
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26

Jiang, Shanghai, Peng He, Luzhen Deng, Mianyi Chen, and Biao Wei. "Monte Carlo Simulation for Polychromatic X-Ray Fluorescence Computed Tomography with Sheet-Beam Geometry." International Journal of Biomedical Imaging 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/7916260.

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X-ray fluorescence computed tomography (XFCT) based on sheet beam can save a huge amount of time to obtain a whole set of projections using synchrotron. However, it is clearly unpractical for most biomedical research laboratories. In this paper, polychromatic X-ray fluorescence computed tomography with sheet-beam geometry is tested by Monte Carlo simulation. First, two phantoms (A and B) filled with PMMA are used to simulate imaging process through GEANT 4. Phantom A contains several GNP-loaded regions with the same size (10 mm) in height and diameter but different Au weight concentration ranging from 0.3% to 1.8%. Phantom B contains twelve GNP-loaded regions with the same Au weight concentration (1.6%) but different diameter ranging from 1 mm to 9 mm. Second, discretized presentation of imaging model is established to reconstruct more accurate XFCT images. Third, XFCT images of phantoms A and B are reconstructed by filter back-projection (FBP) and maximum likelihood expectation maximization (MLEM) with and without correction, respectively. Contrast-to-noise ratio (CNR) is calculated to evaluate all the reconstructed images. Our results show that it is feasible for sheet-beam XFCT system based on polychromatic X-ray source and the discretized imaging model can be used to reconstruct more accurate images.
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27

Alcaraz, Pedro Enrique, and Pierre-Alexandre Blanche. "Advanced volume holographic filter to improve the SNR of polychromatic sources in a noisy environment." Optics Express 29, no. 2 (January 6, 2021): 1232. http://dx.doi.org/10.1364/oe.414217.

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28

Kanzari, M., and B. Rezig. "Optical polychromatic filter by the combination of periodic and quasi-periodic one-dimensional, dielectric photonic bandgap structures." Journal of Optics A: Pure and Applied Optics 3, no. 6 (October 26, 2001): S201—S207. http://dx.doi.org/10.1088/1464-4258/3/6/372.

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29

Tran, Chieu D., and Ricardo J. Furlan. "Acousto-optic tunable filter as a polychromator and its application in multidimensional fluorescence spectrometry." Analytical Chemistry 64, no. 22 (November 15, 1992): 2775–82. http://dx.doi.org/10.1021/ac00046a021.

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30

Buller, Gayle M., JiXiang Liu, Stephen Yue, Jolene A. Bradford, and William L. Godfrey. "Use of Pacific Orange™ Dye with Qdot® Nanocrystals and Other Violet-Excited Dyes in Polychromatic Flow Cytometry." Blood 108, no. 11 (November 16, 2006): 3901. http://dx.doi.org/10.1182/blood.v108.11.3901.3901.

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Abstract Violet-excited fluorochromes are becoming more commonly used in polychromatic flow cytometry experiments. However, violet-excited fluorochromes with emissions longer than 450 nm have been shown to produce small signals relative to the autofluorescent background, usable only on densely expressed antigens, and are sometimes excited by a 488 nm argon ion laser. We have developed a novel violet-excited organic fluor, Pacific Orange™ dye, which has an emission maximum at 551 nm and which is not excited by 488 nm light. Pacific Orange dye is at least twice as bright as the other green emitting violet excitable dyes, Cascade Yellow™ dye and Alexa Fluor® 430 dye. Pacific Orange dye (585/42 nm bandpass filter) can be used for two color immunophenotyping with Pacific Blue ™ dye (450/50 nm band pass filter) with minimal compensation. Data is shown comparing a human CD4/CD8 combination using a direct antibody conjugate with a Zenon® labeling reagent bound to a primary antibody. CD45 antigen is easily resolved with Pacific Orange dye, allowing CD45/SSC gating of leukocytes using violet excitation. Pacific Orange and Pacific Blue dyes can be paired with the violet-excited Fixable Aqua dead cell stain (525/50 nm bandpass filter) to exclude dead cells from immunofluorescence staining. (Figure 1) Finally, a five-color human peripheral blood leukocyte panel is shown using only violet excitation, and pairing Pacific Orange anti-CD8 and Pacific Blue anti-CD4 with Qdot® 605, Qdot 655, and Qdot 705 nanocrystal streptavidin conjugates used sequentially with biotinylated anti-CD19, anti-CD3, and anti-CD56. (Figure 2) Pacific Orange dye provides a tool to transfer detection of abundant target antigens from 488 nm excitation to the violet laser, enabling the use the 488 laser for another marker. In addition, the use of multiple violet-excited dyes can enable the detectection of five or more additional markers to standard laser combinations for greater multiplexing in polychromatic flow cytometry. Figure 1. Immunophenotyping of mixed live and heat-killed human leukocytes using Pacific Orange dye, Pacific Blue dye and the Fixable Aqua dead cell reagent. Live cell events (Fixable Aqua stain-negative) were gated in the histogram (left) for display in the CD4/CD8 scatter plot (right). Figure 1. Immunophenotyping of mixed live and heat-killed human leukocytes using Pacific Orange dye, Pacific Blue dye and the Fixable Aqua dead cell reagent. Live cell events (Fixable Aqua stain-negative) were gated in the histogram (left) for display in the CD4/CD8 scatter plot (right). Figure 2. Five-color immunophenotyping of human leukocytes with Pacific Orange dye, Pacific Blue dye and three Qdot nanocrystal streptavidin conjugates using violet excitation. The Qdot nanocrystal staining was done with sequential staining and washing with biotinylated primary antibodies and streptavidin conjugates. Figure 2. Five-color immunophenotyping of human leukocytes with Pacific Orange dye, Pacific Blue dye and three Qdot nanocrystal streptavidin conjugates using violet excitation. The Qdot nanocrystal staining was done with sequential staining and washing with biotinylated primary antibodies and streptavidin conjugates.
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31

Thomas, Jinto, Ajai Kumar, Vishnu Chaudhari, Kaushal Pandya, and Ranjeet Singh. "Design and development of five-channel interference filter polychromator for SST-1 Thomson scattering system." Fusion Engineering and Design 87, no. 2 (February 2012): 134–40. http://dx.doi.org/10.1016/j.fusengdes.2011.11.010.

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32

Tran, Chieu D., Ricardo J. Furlan, and Jian Lu. "Development of a Multiwavelength Thermal Lens Spectrophotometer Based on an Acousto-Optic Tunable Filter as a Polychromator." Applied Spectroscopy 48, no. 1 (January 1994): 101–6. http://dx.doi.org/10.1366/0003702944027679.

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Instrumentation development of a novel multiwavelength thermal lens spectrophotometer which has the capability of achieving truly multiwavelength excitation is described. The spectrophotometer is based on a new concept by which the sample is excited by multiwavelength excitation beams simultaneously, not sequentially as in previously reported multiwavelength thermal lens apparatus. This was accomplished by use of the acousto-optic tunable filter (AOTF) as a polychromator. Specifically, four different rf signals were simultaneously applied to the filter to enable it to diffract incident multiline laser light into a beam which contained four different wavelengths. This multiwavelength beam was then used to excite the sample, and the corresponding thermal lens signal was measured by a He-Ne probe laser. Compared with other multiwavelength thermal lens instruments, this all-solid-state thermal lens spectrophotometer has advantages that include its ability to simultaneously analyze multicomponent samples in microsecond times scale, without the need for any prior sample preparation. With this apparatus and with the use of a 12-mW multiwavelength excitation beam, the limit of detection for four-component (lanthanide ions) samples is estimated to be 10−6 cm−1, which is similar to the detection limit obtained for one-component samples with the use of a single-wavelength system.
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33

Linden, K. G., G. Shin, and M. D. Sobsey. "Comparative effectiveness of UV wavelengths for the inactivation of Cryptosporidium parvum oocysts in water." Water Science and Technology 43, no. 12 (June 1, 2001): 171–74. http://dx.doi.org/10.2166/wst.2001.0731.

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Cryptosporidium parvum oocysts in water were exposed to distinct wavelength bands of collimated beam ultraviolet (UV) radiation across the germicidal UV wavelength range (210-295 nm) that were emitted from a medium pressure (MP) mercury vapour lamp. The dose of UV radiation transmitted though each narrow bandpass filter was measured utilising potassium ferrioxalate actinometry. Oocyst infectivity was determined using a cell culture assay and titre was expressed as an MPN. The log10 inactivation for each band of radiation was determined for a dose of 2 mJ/cm2. Doses from all wavelengths between 250-275 nm resulted in approximately 2 log10 inactivation of Cryptosporidium parvum oocyst infectivity while doses with wavelengths higher and lower than this range were less effective. Because polychromatic radiation from MP UV lamps had about the same germicidal activity between the wavelengths of 250-275 nm for inactivation of oocyst infectivity, there was no unique advantage of MP UV over low pressure (LP) UV except for the simultaneous delivery of a wide range of germicidal wavelengths.
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Okajima, Hajime, and Hiro-O. Hamaguchi. "Fast Low Frequency (Down to 10 cm−1) Multichannel Raman Spectroscopy Using an Iodine Vapor Filter." Applied Spectroscopy 63, no. 8 (August 2009): 958–60. http://dx.doi.org/10.1366/000370209788964368.

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We have constructed a multi-channel Raman spectrometer that is capable of recording the low frequency region down to 5 cm−1 with a measurement time of a few tenths of a second. An iodine vapor filter, which uses a narrow (∼0.03 cm−1) absorption line of iodine for Rayleigh scattering elimination, is combined with a multi-channel Raman spectrometer composed of a single polychromator and a charge-coupled device (CCD) camera. Thanks to the high Rayleigh scattering elimination efficiency of the filter, which is over 106, Raman spectra of microcrystalline l-cystine from −300 cm−1 to 1000 cm−1 are simultaneously measurable with a small gap of 10 cm−1 (–5 cm−1 to 5 cm−1). Although raw spectra contain many sharp spikes due to the fine structures of iodine absorption, they can be correctly compensated with the use of a transmittance spectrum measured under the same experimental conditions. Many Raman bands including the 9.8 cm−1 band are measured with a high signal-to-noise ratio in both the Stokes and anti-Stokes sides with a measurement time as short as 0.2 s.
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Attar, K. M. "Coincidence Profiles for Sulfur Emission at 180.73 nm (Third Order) in ICP-AES." Applied Spectroscopy 42, no. 8 (November 1988): 1493–99. http://dx.doi.org/10.1366/0003702884429689.

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Coincidence profiles of eleven prevalent concomitant elements, on the sulfur emission line at 180.73 nm in the third order, were procured by scanning the sulfur channel of a vacuum argon ICP-AES using the polychromator primary slit. VUV, as well as UV emission lines above 250 nm in the second order were observed, despite the fact that an interference filter with less than 2% transmission above 250 nm was located before the channel photomultiplier. Spectral interferences from Ca (1000 mg/L), Si (1000 mg/L), Cr (200 mg/L), and Ti (200 mg/L) were attributed to VUV emission lines; those from Mn (200 mg/L) to a UV line above 250 nm in the second order; and those from Fe (1000 mg/L) and V (200 mg/L) to VUV as well as UV lines. Background enhancement was exhibited by Al (1000 mg/L), Ni (200 mg/L), and Mg (1000 mg/L). Cu (200 mg/L) did not interfere. A simple procedure for distinguishing VUV from UV lines, by using the argon purge nozzle of the vacuum ICP-AES as an air optical filter, is demonstrated. The procedure is useful for facilities where a scanning monochromator is not available.
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Jones, Bernard L., Nivedh Manohar, Francisco Reynoso, Andrew Karellas, and Sang Hyun Cho. "Experimental demonstration of benchtop x-ray fluorescence computed tomography (XFCT) of gold nanoparticle-loaded objects using lead- and tin-filtered polychromatic cone-beams." Physics in Medicine and Biology 57, no. 23 (November 8, 2012): N457—N467. http://dx.doi.org/10.1088/0031-9155/57/23/n457.

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37

Moseshvili, Gulnara Grigorievna, Nataliya Borisovna Korchazhkina, and Madina Zaudinovna Dugieva. "The effect of the combined use of polarized light and immunomodulator on the cytokine profile in patients with HPV-associated cervicitis." Fizioterapevt (Physiotherapist), no. 2 (February 1, 2021): 56–65. http://dx.doi.org/10.33920/med-14-2104-07.

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Taking into account the literature data on the significance of the mucous membranes in providing an immune filter, and cervical mucus in providing an immune response due to the high content of the main mediators of the development of a local inflammatory response, i.e. anti-inflammatory cytokines, which play a major role in the regulation of the immune response and the formation of local antiviral and antitumor immunity, we studied the cytokine profile in patients with HPV-associated cervicitis and the effect of the combined use of polarized light and an immunomodulator on their content, depending on the viral load. The purpose of the work is to study the effect of the combined exposure to blue monochromatic polarized incoherent light and polychromatic visible and infrared polarized light in combination with Imiquimod 5% cream for external use on the state of the cytokine profile in the cervical mucus in patients with HPV-associated cervicitis. Material and methods. The study included 60 patients with an HPV-associated cervicitis with the history of at least 1 year, aged 20 to 35 years, who were randomly divided into three groups: the main group of 20 patients who underwent course exposure to blue monochromatic polarized incoherent light on the projection of the carotid arteries and polychromatic visible and infrared polarized light on the cervix in combination with Imiquimod 5% cream for external use (complex 1); a comparison group of 20 patients who underwent the exposure to polychromatic visible and infrared polarized light on the cervix in combination with the topical cream, Imiquimod 5% (complex 2); a control group of 20 patients who underwent a course of local effects on the cervix with the cream Imiquimod 5% and 20 healthy women of similar age, whose the survey data were taken as a norm. To assess the cytokine state in patients with HPV-associated cervicitis, the levels of IL-1β, IL-2, IL-10, IFNa, IFNy, and TNFa in the cervical mucus were studied before and after the course of treatment by the enzyme immunoassay method. The results of the research and the discussion. Prior to the treatment, certain differences were found depending on the viral load. In patients with a low viral load, interferon levels of IFNα and IFNγ were increased by 55% (p < 0.05) and 93%, respectively (p < 0.01), compared with those of healthy women, with a significant decrease in the content of IL-10 — by 85% (p < 0.01), IL-2 — by 53% (p < 0.05) and TNFα — by 56% (p < 0.05), the content of IL-1β was increased only by 8% (p > 0.05). When analyzing cytokine levels in patients with an increased viral load, IFNα was increased by 48% (p < 0.05) and IFNγ — by 62% (p < 0.05), as well as IL-1β — by 59% (p < 0.05), and TNFα — by 37% (p < 0.05), compared to healthy women, with a significant decrease in IL-10 and IL-2 — by 53% and 56%, respectively (p < 0.05). The increase in the concentration of TNFα and IFNγ with an increased viral load was slightly lower. In patients with a significant viral load, interferons IFNα and IFNγ were increased by 35% and 40%, accordingly (p < 0.05), IL-1β — by 17.9% (p < 0.05) and IL-10 — by 14.1% against the background of a slight decrease in the content of TNFα — by 14.5% (p >0.05) and a highly significant 2.26-fold decrease in IL-2 — (p < 0.05), which play an important role in the regulation of the Th1 immune response. After the treatment, in patients of the main group (complex 1) and a comparison group (complex 2) with no significant differences, the positive dynamics was observed, manifested in lowering the initially increased concentrations of TNFα and IFNγ, IL-1β and IL-10 approaching the level of healthy individuals; in the control group, the decrease of the initially increased IL-2 and TNFα was noted, and, although there was a positive dynamics of all the studied indicators, it was less pronounced. Conclusion. The obtained data indicate a pronounced immunocorrective effect of the combined use of blue monochromatic polarized incoherent light on the projection of the carotid arteries and polychromatic visible and infrared polarized light on the cervix in combination with Imiquimod 5% cream for external use in patients with chronic cervicitis associated with papillomavirus infection, which is confirmed by an improvement in the cytokine profile.
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38

Behrendt, Andreas, and Jens Reichardt. "Atmospheric temperature profiling in the presence of clouds with a pure rotational Raman lidar by use of an interference-filter-based polychromator." Applied Optics 39, no. 9 (March 20, 2000): 1372. http://dx.doi.org/10.1364/ao.39.001372.

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39

Neale, P. J., A. L. Pritchard, and R. Ihnacik. "UV effects on the primary productivity of picophytoplankton: biological weighting functions and exposure response curves of <i>Synechococcus</i>." Biogeosciences 11, no. 10 (May 28, 2014): 2883–95. http://dx.doi.org/10.5194/bg-11-2883-2014.

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Abstract. A model that predicts UV effects on marine primary productivity using a biological weighting function (BWF) coupled to the photosynthesis–irradiance response (BWF/P-E model) has been implemented for two strains of the picoplanktonic cyanobacteria Synechococcus, WH7803 and WH8102, which were grown at two irradiances (77 and 174 μmol m−2 s−1 photosynthetically available radiation (PAR)) and two temperatures (20 and 26 °C). The model was fit using photosynthesis measured in a polychromatic incubator with 12 long-pass filter configurations with 50% wavelength cutoffs ranging from 291 to 408 nm, giving an effective wavelength range of 280–400 nm. Examination of photosynthetic response vs. weighted exposure revealed that repair rate progressively increases at low exposure but reaches a maximum rate above a threshold exposure ("Emax"). Adding Emax as a parameter to the BWF/P-E model provided a significantly better fit to Synechococcus data than the existing "E" or "T" models. Sensitivity to UV inhibition varied with growth conditions for both strains, but this was mediated mainly by variations in Emax for WH8102 while both the BWF and Emax changed for WH7803. Higher growth temperature was associated with a considerable reduction in sensitivity, consistent with an important role of repair in regulating sensitivity to UV. Based on nominal water column conditions (noon, solstice, 23° latitude, "blue" water), the BWFEmax/P-E model estimates that UV + PAR exposure inhibits Synechococcus photosynthesis from 78 to 91% at 1 m, and integrated productivity to 150 m 17–29% relative to predicted rates in the absence of inhibition.
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40

Neale, P. J., A. L. Pritchard, and R. Ihnacik. "UV effects on the primary productivity of picophytoplankton: biological weighting functions and exposure response curves of <i>Synechococcus</i>." Biogeosciences Discussions 10, no. 12 (December 11, 2013): 19449–84. http://dx.doi.org/10.5194/bgd-10-19449-2013.

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Abstract. A model that predicts UV effects on marine primary productivity using a biological weighting function (BWF) coupled to the photosynthesis-irradiance response (BWF/P-E model) has been implemented for two strains of the picoplanktonic cyanobacteria, Synechococcus, WH7803 and WH8102, which were grown at two irradiances (77 and 174 μmol m−2 s−1 PAR) and two temperatures (20 °C and 26 °C). The model was fit using photosynthesis measured in a polychromatic incubator with 12 long-pass filter configurations with 50% wavelength cutoffs ranging from 291 to 408 nm, giving an effective wavelength range of 280–400 nm. Examination of photosynthetic response vs weighted exposure revealed that repair rate progressively increases at low exposure but reaches a maximum rate above a threshold exposure ("Emax"). Adding Emax as a parameter to the BWF/P-E model provided a significantly better fit to Synechococcus data than the existing "E" or "T" models. Sensitivity to UV inhibition varied with growth conditions for both strains, but this was mediated mainly by variations in Emax for WH8102 while both the BWF and Emax changed for WH7803. Higher growth temperature was associated with a considerable reduction in sensitivity, consistent with an important role of repair in regulating sensitivity to UV. Based on nominal water column conditions (noon, solstice, 23° latitude, "blue" water), the BWFEmax/P-E model estimates that UV + PAR exposure inhibits Synechococcus photosynthesis from 77–91% at 1 m, and integrated productivity to 150 m 15–27% relative to predicted rates in the absence of inhibition.
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41

Eberhard, Matthias, Victor Mergen, Kai Higashigaito, Thomas Allmendinger, Robert Manka, Thomas Flohr, Bernhard Schmidt, Andre Euler, and Hatem Alkadhi. "Coronary Calcium Scoring with First Generation Dual-Source Photon-Counting CT—First Evidence from Phantom and In-Vivo Scans." Diagnostics 11, no. 9 (September 18, 2021): 1708. http://dx.doi.org/10.3390/diagnostics11091708.

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We evaluated the accuracy of coronary artery calcium (CAC) scoring on a dual-source photon-counting detector CT (PCD-CT). An anthropomorphic chest phantom underwent ECG-gated sequential scanning on a PCD-CT at 120 kV with four radiation dose levels (CTDIvol, 2.0–8.6 mGy). Polychromatic images at 120 kV (T3D) and virtual monoenergetic images (VMI), from 60 to 75 keV without quantum iterative reconstruction (no QIR) and QIR strength levels 1–4, were reconstructed. For reference, the same phantom was scanned on a conventional energy-integrating detector CT (120 kV; filtered back projection) at identical radiation doses. CAC scoring in 20 patients with PCD-CT (120 kV; no QIR and QIR 1–4) were included. In the phantom, there were no differences between CAC scores of different radiation doses (all, p > 0.05). Images with 70 keV, no QIR (CAC score, 649); 65 keV, QIR 3 (656); 65 keV; QIR4 (648) and T3D, QIR4 (656) showed a <1% deviation to the reference (653). CAC scores significantly decreased at increasing QIR levels (all, p < 0.001) and for each 5 keV-increase (all, p < 0.001). Patient data (median CAC score: 86 [inter-quartile range: 38–978] at 70 keV) confirmed relationships and differences between reconstructions from the phantom. First phantom and in-vivo experience with a clinical dual-source PCD-CT system shows accurate CAC scoring with VMI reconstructions at different radiation dose levels.
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42

Steinemann, Alexandra, Vivien Bromundt, Sarah Chellappa, Sylvia Frey, Christina Schmidt, Torsten Schlote, David Goldblum, and Christian Cajochen. "Evaluation of Visual Comfort and Mental Effort Under Different Light Conditions for Ultraviolet-Absorbing and Additional Blue-Filtering Intraocular Lenses for Cataract Surgery." Klinische Monatsblätter für Augenheilkunde 236, no. 04 (January 7, 2019): 398–404. http://dx.doi.org/10.1055/a-0810-0302.

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Abstract Patients and Methods Patients with an ultraviolet blocking lens (UV) (n = 5) or blue filter lens (BB) (n = 8) after intraocular lens (IOL) replacement for cataract and age-adjusted controls (AACs) (n = 16) underwent a balanced crossover within-subject design. After 1.5 h of dark adaptation, they were exposed to polychromatic light at 6500 K (blue-enriched) and 2500 K and 3000 K (non-blue-enriched) for 2 hours in the evening. Visual comfort and mental effort were repeatedly assessed by the Visual Analogue Scale (0 – 100) and the Visual Comfort and Mental Effort Rating Scale (0 – 100) for each light condition. The results were compared using mixed model analysis. Results The mean (± SD) age for AAC and patients with UV or BB was 69.8 ± 6.2 y, 70.8 ± 4 y, and 63.6 ± 5.6 y, respectively. Irrespective of the light condition, patients with UV and BB felt mentally more tired during the experiments compared to AACs (F = 6.15, p = 0.003). However, patients with BB were mentally more motivated to perform the exercises compared to patients with UV and AACs (F = 8.1, p < 0.001). Patients with BB perceived ambient light as less glary (F = 4.71, p = 0.01) than patients with UV. Blue ambient light was felt less intensely in patients with BB (F = 2.51, p = 0.042) compared to those with UV and the AACs. Conclusion Lens replacement in older cataract patients may increase visual comfort and minimize mental effort. While subtle, the magnitude of these effects may depend on the type of intraocular lens. BB intraocular lenses may have potential benefits, as ambient light is perceived as having less glare and less visual tension.
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43

Li, Fangyu, Jie Qi, Bin Lyu, and Kurt J. Marfurt. "Multispectral coherence." Interpretation 6, no. 1 (February 1, 2018): T61—T69. http://dx.doi.org/10.1190/int-2017-0112.1.

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Seismic coherence is a routine measure of seismic reflection similarity for interpreters seeking structural boundary and discontinuity features that may be not properly highlighted on original amplitude volumes. One mostly wishes to use the broadest band seismic data for interpretation. However, because of thickness tuning effects, spectral components of specific frequencies can highlight features of certain thicknesses with higher signal-to-noise ratio than others. Seismic stratigraphic features (e.g., channels) may be buried in the full-bandwidth data, but can be “lit up” at certain spectral components. For the same reason, coherence attributes computed from spectral voice components (equivalent to a filter bank) also often provide sharper images, with the “best” component being a function of the tuning thickness and the reflector alignment across faults. Although one can corender three coherence images using red-green-blue (RGB) blending, a display of the information contained in more than three volumes in a single image is difficult. We address this problem by combining covariance matrices for each spectral component, adding them together, resulting in a “multispectral” coherence algorithm. The multispectral coherence images provide better images of channel incisement, and they are less noisy than those computed from the full bandwidth data. In addition, multispectral coherence also provides a significant advantage over RGB blended volumes. The information content from unlimited spectral voices can be combined into one volume, which is useful for a posteriori/further processing, such as color corendering display with other related attributes, such as petrophysics parameters plotted against a polychromatic color bar. We develop the value of multispectral coherence by comparing it with the RGB blended volumes and coherence computed from spectrally balanced, full-bandwidth seismic amplitude volume from a megamerge survey acquired over the Red Fork Formation of the Anadarko Basin, Oklahoma.
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44

Hammann, E., A. Behrendt, F. Le Mounier, and V. Wulfmeyer. "Temperature profiling of the atmospheric boundary layer with rotational Raman lidar during the HD(CP)<sup>2</sup> observational prototype experiment." Atmospheric Chemistry and Physics Discussions 14, no. 21 (November 21, 2014): 28973–9018. http://dx.doi.org/10.5194/acpd-14-28973-2014.

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Abstract. The temperature measurements of the Rotational Raman Lidar of the University of Hohenheim (UHOH RRL) during the High Definition of Clouds and Precipitation for advancing Climate Prediction (HD(CP)2 Prototype Experiment (HOPE) in April and May 2013 are discussed. The lidar consists of a frequency-tripled Nd:YAG laser at 355 nm with 10 W average power at 50 Hz, a two-mirror scanner, a 40 cm receiving telescope and a highly efficient polychromator with cascading interference filters for separating four signals: the elastic backscatter signal, two rotational Raman signals with different temperature dependence, and the vibrational Raman signal of water vapor. The main measurement variable of the UHOH RRL is temperature. For the HOPE campaign, the lidar receiver was optimized for high and low background levels, respectively, with a novel switch for the passband of the second rotational Raman channel. The instrument delivers atmospheric profiles of water vapor mixing ratio as well as particle backscatter coefficient and particle extinction coefficient as further products. As examples for the measurement performance, measurements of the temperature gradient and water vapor mixing ratio revealing the development of the atmospheric boundary layer within 25 h are presented. As expected from simulations, a significant advance during nighttime was achieved with the new low-background setting. A two-mirror scanner allows for measurements in different directions. When pointing the scanner to low elevation, measurements close to the ground become possible which are otherwise impossible due to the non-total overlap of laser beam and receiving telescope field-of-view in the near range. We present an example of a low-level temperature measurement which resolves the temperature gradient at the top of the stable nighttime boundary layer a hundred meters above the ground.
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45

Hammann, E., A. Behrendt, F. Le Mounier, and V. Wulfmeyer. "Temperature profiling of the atmospheric boundary layer with rotational Raman lidar during the HD(CP)<sup>2</sup> Observational Prototype Experiment." Atmospheric Chemistry and Physics 15, no. 5 (March 12, 2015): 2867–81. http://dx.doi.org/10.5194/acp-15-2867-2015.

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Abstract. The temperature measurements of the rotational Raman lidar of the University of Hohenheim (UHOH RRL) during the High Definition of Clouds and Precipitation for advancing Climate Prediction (HD(CP)2) Observation Prototype Experiment (HOPE) in April and May 2013 are discussed. The lidar consists of a frequency-tripled Nd:YAG laser at 355 nm with 10 W average power at 50 Hz, a two-mirror scanner, a 40 cm receiving telescope, and a highly efficient polychromator with cascading interference filters for separating four signals: the elastic backscatter signal, two rotational Raman signals with different temperature dependence, and the vibrational Raman signal of water vapor. The main measurement variable of the UHOH RRL is temperature. For the HOPE campaign, the lidar receiver was optimized for high and low background levels, with a novel switch for the passband of the second rotational Raman channel. The instrument delivers atmospheric profiles of water vapor mixing ratio as well as particle backscatter coefficient and particle extinction coefficient as further products. As examples for the measurement performance, measurements of the temperature gradient and water vapor mixing ratio revealing the development of the atmospheric boundary layer within 25 h are presented. As expected from simulations, a reduction of the measurement uncertainty of 70% during nighttime was achieved with the new low-background setting. A two-mirror scanner allows for measurements in different directions. When pointing the scanner to low elevation, measurements close to the ground become possible which are otherwise impossible due to the non-total overlap of laser beam and receiving telescope field of view in the near range. An example of a low-level temperature measurement is presented which resolves the temperature gradient at the top of the stable nighttime boundary layer 100 m above the ground.
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46

Gomi, Tsutomu, Hidetake Hara, Yusuke Watanabe, and Shinya Mizukami. "Improved digital chest tomosynthesis image quality by use of a projection-based dual-energy virtual monochromatic convolutional neural network with super resolution." PLOS ONE 15, no. 12 (December 31, 2020): e0244745. http://dx.doi.org/10.1371/journal.pone.0244745.

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We developed a novel dual-energy (DE) virtual monochromatic (VM) very-deep super-resolution (VDSR) method with an unsharp masking reconstruction algorithm (DE–VM–VDSR) that uses projection data to improve the nodule contrast and reduce ripple artifacts during chest digital tomosynthesis (DT). For estimating the residual errors from high-resolution and multiscale VM images from the projection space, the DE–VM–VDSR algorithm employs a training network (mini-batch stochastic gradient-descent algorithm with momentum) and a hybrid super-resolution (SR) image [simultaneous algebraic reconstruction technique (SART) total-variation (TV) first-iterative shrinkage–thresholding algorithm (FISTA); SART–TV–FISTA] that involves subjective reconstruction with bilateral filtering (BF) [DE–VM–VDSR with BF]. DE-DT imaging was accomplished by pulsed X-ray exposures rapidly switched between low (60 kV, 37 projection) and high (120 kV, 37 projection) tube-potential kVp by employing a 40° swing angle. This was followed by comparison of images obtained employing the conventional polychromatic filtered backprojection (FBP), SART, SART–TV–FISTA, and DE–VM–SART–TV–FISTA algorithms. The improvements in contrast, ripple artifacts, and resolution were compared using the signal-difference-to-noise ratio (SDNR), Gumbel distribution of the largest variations, radial modulation transfer function (radial MTF) for a chest phantom with simulated ground-glass opacity (GGO) nodules, and noise power spectrum (NPS) for uniform water phantom. The novel DE–VM–VDSR with BF improved the overall performance in terms of SDNR (DE–VM–VDSR with BF: 0.1603, without BF: 0.1517; FBP: 0.0521; SART: 0.0645; SART–TV–FISTA: 0.0984; and DE–VM–SART–TV–FISTA: 0.1004), obtained a Gumbel distribution that yielded good images showing the type of simulated GGO nodules used in the chest phantom, and reduced the ripple artifacts. The NPS of DE–VM–VDSR with BF showed the lowest noise characteristics in the high-frequency region (~0.8 cycles/mm). The DE–VM–VDSR without BF yielded an improved resolution relative to that of the conventional reconstruction algorithms for radial MTF analysis (0.2–0.3 cycles/mm). Finally, based on the overall image quality, DE–VM–VDSR with BF improved the contrast and reduced the high-frequency ripple artifacts and noise.
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47

Behrendt, A., V. Wulfmeyer, E. Hammann, S. K. Muppa, and S. Pal. "Profiles of second- to third-order moments of turbulent temperature fluctuations in the convective boundary layer: first measurements with Rotational Raman Lidar." Atmospheric Chemistry and Physics Discussions 14, no. 21 (November 21, 2014): 29019–55. http://dx.doi.org/10.5194/acpd-14-29019-2014.

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Abstract. The rotational Raman lidar of the University of Hohenheim (UHOH) measures atmospheric temperature profiles during daytime with high resolution (10 s, 109 m). The data contain low noise errors even in daytime due to the use of strong UV laser light (355 nm, 10 W, 50 Hz) and a very efficient interference-filter-based polychromator. In this paper, we present the first profiling of the second- to forth-order moments of turbulent temperature fluctuations as well as of skewness and kurtosis in the convective boundary layer (CBL) including the interfacial layer (IL). The results demonstrate that the UHOH RRL resolves the vertical structure of these moments. The data set which is used for this case study was collected in western Germany (50°53'50.56′′ N, 6°27'50.39′′ E, 110 m a.s.l.) within one hour around local noon on 24 April 2013 during the Intensive Observations Period (IOP) 6 of the HD(CP)2 Observational Prototype Experiment (HOPE), which is embedded in the German project HD(CP)2 (High-Definition Clouds and Precipitation for advancing Climate Prediction). First, we investigated profiles of the noise variance and compared it with estimates of the statistical temperature measurement uncertainty Δ T based on Poisson statistics. The agreement confirms that photon count numbers obtained from extrapolated analog signal intensities provide a lower estimate of the statistical errors. The total statistical uncertainty of a 20 min temperature measurement is lower than 0.1 K up to 1050 m a.g.l. at noontime; even for single 10 s temperature profiles, it is smaller than 1 K up to 1000 m a.g.l.. Then we confirmed by autocovariance and spectral analyses of the atmospheric temperature fluctuations that a temporal resolution of 10 s was sufficient to resolve the turbulence down to the inertial subrange. This is also indicated by the profile of the integral scale of the temperature fluctuations, which was in the range of 40 to 120 s in the CBL. Analyzing then profiles of the second-, third-, and forth-order moments, we found the largest values of all moments in the IL around the mean top of the CBL which was located at 1230 m a.g.l. The maximum of the variance profile in the IL was 0.40 K2 with 0.06 and 0.08 K2 for the sampling error and noise error, respectively. The third-order moment was not significantly different from zero inside the CBL but showed a negative peak in the IL with a minimum of −0.72 K3 and values of 0.06 and 0.14 K3 for the sampling and noise errors, respectively. The forth-order moment and kurtosis values throughout the CBL were quasi-normal.
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48

Behrendt, A., V. Wulfmeyer, E. Hammann, S. K. Muppa, and S. Pal. "Profiles of second- to fourth-order moments of turbulent temperature fluctuations in the convective boundary layer: first measurements with rotational Raman lidar." Atmospheric Chemistry and Physics 15, no. 10 (May 20, 2015): 5485–500. http://dx.doi.org/10.5194/acp-15-5485-2015.

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Abstract. The rotational Raman lidar (RRL) of the University of Hohenheim (UHOH) measures atmospheric temperature profiles with high resolution (10 s, 109 m). The data contain low-noise errors even in daytime due to the use of strong UV laser light (355 nm, 10 W, 50 Hz) and a very efficient interference-filter-based polychromator. In this paper, the first profiling of the second- to fourth-order moments of turbulent temperature fluctuations is presented. Furthermore, skewness profiles and kurtosis profiles in the convective planetary boundary layer (CBL) including the interfacial layer (IL) are discussed. The results demonstrate that the UHOH RRL resolves the vertical structure of these moments. The data set which is used for this case study was collected in western Germany (50°53'50.56'' N, 6°27'50.39'' E; 110 m a.s.l.) on 24 April 2013 during the Intensive Observations Period (IOP) 6 of the HD(CP)2 (High-Definition Clouds and Precipitation for advancing Climate Prediction) Observational Prototype Experiment (HOPE). We used the data between 11:00 and 12:00 UTC corresponding to 1 h around local noon (the highest position of the Sun was at 11:33 UTC). First, we investigated profiles of the total noise error of the temperature measurements and compared them with estimates of the temperature measurement uncertainty due to shot noise derived with Poisson statistics. The comparison confirms that the major contribution to the total statistical uncertainty of the temperature measurements originates from shot noise. The total statistical uncertainty of a 20 min temperature measurement is lower than 0.1 K up to 1050 m a.g.l. (above ground level) at noontime; even for single 10 s temperature profiles, it is smaller than 1 K up to 1020 m a.g.l. Autocovariance and spectral analyses of the atmospheric temperature fluctuations confirm that a temporal resolution of 10 s was sufficient to resolve the turbulence down to the inertial subrange. This is also indicated by the integral scale of the temperature fluctuations which had a mean value of about 80 s in the CBL with a tendency to decrease to smaller values towards the CBL top. Analyses of profiles of the second-, third-, and fourth-order moments show that all moments had peak values in the IL around the mean top of the CBL which was located at 1230 m a.g.l. The maximum of the variance profile in the IL was 0.39 K2 with 0.07 and 0.11 K2 for the sampling error and noise error, respectively. The third-order moment (TOM) was not significantly different from zero in the CBL but showed a negative peak in the IL with a minimum of −0.93 K3 and values of 0.05 and 0.16 K3 for the sampling and noise errors, respectively. The fourth-order moment (FOM) and kurtosis values throughout the CBL were not significantly different to those of a Gaussian distribution. Both showed also maxima in the IL but these were not statistically significant taking the measurement uncertainties into account. We conclude that these measurements permit the validation of large eddy simulation results and the direct investigation of turbulence parameterizations with respect to temperature.
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49

Michael, Bok, and Cronin Thomas. "Multiple optical filters contribute to polychromatic ultraviolet sensitivity in stomatopod crustaceans." Frontiers in Physiology 4 (2013). http://dx.doi.org/10.3389/conf.fphys.2013.25.00033.

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50

Patterson, C. R., K. I. Ignatiev, A. Guvenilir, J. D. Haase, R. Morano, Z. U. Rek, and S. R. Stock. "Nondestructive Determination of the Depth of Different Texture Components in Polycrystalline Samples." MRS Proceedings 590 (1999). http://dx.doi.org/10.1557/proc-590-253.

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ABSTRACTThe surface and the center average textures (macrotexture) of plates of many alloys differ substantially, and nondestructive methods for determining the depth of different texture components would be very useful in various applications. This report evaluates one method based on recording microbeam transmission Laue patterns as a function of sample-detector separation and on tracing the diffracted rays back to their physical origin. Polychromatic synchrotron x-radiation and absorption edge filters are used. Results from sections of Al-Li 2090 T8E41 plates are reported, and limitations of the ray tracing technique are discussed
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