scholarly journals The Degree of Linear Polarization for Suspended Particle Fields from Diverse Natural Waters

2021 ◽  
Vol 2 ◽  
Author(s):  
Siyao Zhai ◽  
Michael Twardowski
Keyword(s):  
Refractive Index ◽  
Linear Polarization ◽  
Natural Waters ◽  
Suspended Particle ◽  
Lookup Table ◽  
Homogeneous Sphere ◽  
Angle Scattering ◽  
Spectral Attenuation ◽  
Particle Shapes ◽  
Good Agreement

The Degree of Linear Polarization (DoLP) for unperturbed particle fields in waters from six diverse regions around the globe was measured with the custom Multi-Angle Scattering Optical Tool (MASCOT). DoLP here is defined as the ratio of two elements of Mueller scattering matrix, i.e., -M12/M11. Field sites covered inland waters, coastal oceans and open oceans, including both ocean color Case I and II water types. The angular shape of the measured particulate DoLP was analyzed in detail for each field site and for the ensemble average. Three parameters used to quantitatively characterize DoLP shape were the symmetry with respect to 90°, peak magnitude, and peak angle of measured DoLP angular curve. Vertical profiles of particulate DoLP were analyzed with maximum recorded depth of 111 m. Converse to Rayleigh scatterers, we found measured particulate DoLPs were not symmetric with respect to 90°. On average, DoLP peaks were shifted slightly toward larger angles, with most falling between estimated values of 90° and 95°. All particulate DoLP peak magnitudes generally varied within [0.6, 0.9]. Lorenz-Mie (homogeneous sphere) light scattering theory was used to construct a new inversion for bulk particulate refractive index from a lookup table based on DoLP and spectral attenuation measurements. We compared the Mie-DoLP-based particulate refractive index retrieval with the backscattering-based model from (Twardowski et al., J. Geophys. Res., 2001, 106(C7), 14,129–14,142). Particulate refractive index retrieved with the two models were in some cases comparable. At two of the six field sites we saw good agreement between the two models, whereas at another two field sites we observed large discrepancies between the two models. Further investigation on the choice of the modeled particle shapes and compositions may improve this retrieval approach. Results are compatible with previous studies on DoLPs in natural waters and comprehensive observations are provided on the particulate DoLP angular shape, vertical profile and global distributions that are important for future vector radiative transfer simulations. This study is relevant to future PACE polarimeters and associated remote retrieval of oceanic particle composition using polarimetry.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

Analysis of Fractional Composition and Specific Surface of Silicone Dioxide Nanopowders

2020 ◽  
Vol 992 ◽  
pp. 551-555
Author(s):  
O.N. Kravtsova ◽  
G.G. Vinokurov ◽  
N.F. Struchkov
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fractional Composition ◽  
Nanosized Powder ◽  
Nanosized Powders ◽  
Powder Mixtures ◽  
Angle Scattering ◽  
Intermediate Value ◽  
Particle Shapes

For the development of new compositions of modified powder mixtures a comprehensive analysis of the technical characteristics of powder additives is required. The specific surfaces of nanosized powders of "Tarkosil" silicone dioxide were determined by the experimental method. Therefore, at present, the estimating relationships of sizes, particles shapes and specific surface area of nanosized powder is relevant scientific and practical task. And the particles shape was evaluated by the values of these surfaces. Using the method of small-angle scattering the functions of distribution of the modifying powders particles on their sizes were estimated, and the average values of particles size of "Tarkosil" powder were specified The particle shape of the modifying powders has been estimated according to the specific surface values. The particle shapes of T50 powders are close to isometric (a ball, a cube); particle shapes of T150 powders correspond to a tetrahedron, the particle size T80 and T110 corresponds to the intermediate value of the specific surface area.

Study of the 1459-keV level in 19F by the 19F(p,p′γ)19F reaction

1970 ◽  
Vol 48 (7) ◽  
pp. 827-833 ◽  
Author(s):  
S. T. Lam ◽  
A. E. Litherland ◽  
J. J. Simpson
Keyword(s):  
Angular Distribution ◽  
Single Crystal ◽  
Linear Polarization ◽  
Proton Energy ◽  
Branching Ratios ◽  
Mixing Ratio ◽  
Γ Ray ◽  
Good Agreement

The 1459-keV level of 19F was populated by the 19F(p,p′γ)19F reaction at a proton energy of 2.78 MeV. The E2/M1 mixing ratio for the 1459 → 110 keV transition was determined to be [Formula: see text] from a combination of the γ-ray angular distribution and linear polarization and the nuclear lifetime. The γ-ray angular distribution was measured with a coaxial Ge(Li) detector and the γ-ray linear polarization with a planar Ge(Li) detector. The corresponding E2 and M1 transition strengths for a lifetime of 0.084 ± 0.020 ps are found to be [Formula: see text] and 0.10 ± 0.03 W.u. respectively. They are in good agreement with the particle–hole calculations of Benson and Flowers. The branching ratios of the 1459-keV level agree well with those of Poletti et al. The γ-ray transitions from the 1459-keV level provide a good example for demonstrating the usefulness of a single crystal Ge(Li) polarimeter.

Computer studies of fast ion trajectories in crystals

1968 ◽  
Vol 46 (6) ◽  
pp. 503-516 ◽  
Author(s):  
D. V. Morgan ◽  
D. van Vliet
Keyword(s):  
Large Angle ◽  
Classical Dynamics ◽  
Perfect Lattice ◽  
Fast Ions ◽  
Angle Scattering ◽  
Initial Work ◽  
Fast Ion ◽  
Thermal Vibrations ◽  
Computer Studies ◽  
Good Agreement

A computer program has been developed which follows the trajectories of fast ions in crystals, based on the assumption of classical dynamics and binary collisions. Initial work has been directed at various aspects of proton channeling in copper in the energy range 5–500 keV. The critical angle and distance of closest approach in a perfect lattice have been evaluated for both rows and planes and compare well with the predictions of the continuum model as developed by Lindhard (1965). We also discuss the overlap of close-packed rows and planes, and the modifications necessary to the basic theory when thermal vibrations are introduced. Experiments have been simulated directly by obtaining a statistical analysis of the velocity distribution of protons reflected from a (100) face of copper and transmitted through a thin (~1800 Â) crystal. In reflection, distinct minima were obtained along directions corresponding to close-packed rows and planes, in good agreement with experimental "blocking patterns" (Nelson 1967a). Transmission patterns also revealed a lack of large-angle scattering parallel to close-packed planes, analogous to the white arms observed experimentally with thinner crystals.

Analysis of Thermal Variation of Length and Refractive Index of Lead Fluoride to Study its Optical Properties

1989 ◽  
Vol 172 ◽  
Author(s):  
T. S. Aurora ◽  
D. O. Pederson ◽  
S. M. Day
Keyword(s):  
Refractive Index ◽  
Room Temperature ◽  
Linear Thermal Expansion ◽  
Small Variation ◽  
Published Data ◽  
Thermal Variation ◽  
Lead Fluoride ◽  
Superionic Phase Transition ◽  
Lorenz Relation ◽  
Good Agreement

AbstractLinear thermal expansion and refractive index variation have been measured in lead fluoride with a laser interferometer as a function of temperature. Data has been analyzed using the Lorentz-Lorenz relation. Molecular polarizability, band gap, variation of refractive index with density, and strain-polarizability parameter have been studied as a function of temperature. They exhibit a small variation with temperature except near the superionic phase transition where the variation appears to be more pronounced. The results are in good agreement with the published data near room temperature.

scholarly journals Aerosol retrieval from multiangle, multispectral photopolarimetric measurements: importance of spectral range and angular resolution

2015 ◽  
Vol 8 (6) ◽  
pp. 2625-2638 ◽  
Author(s):  
L. Wu ◽  
O. Hasekamp ◽  
B. van Diedenhoven ◽  
B. Cairns
Keyword(s):  
Refractive Index ◽  
Spectral Range ◽  
Angular Resolution ◽  
Single Scattering ◽  
Microphysical Properties ◽  
Aerosol Retrieval ◽  
Spectral Ranges ◽  
Shortwave Infrared ◽  
Aerosol Properties ◽  
Good Agreement

Abstract. We investigated the importance of spectral range and angular resolution for aerosol retrieval from multiangle photopolarimetric measurements over land. For this purpose, we use an extensive set of simulated measurements for different spectral ranges and angular resolutions and subsets of real measurements of the airborne Research Scanning Polarimeter (RSP) carried out during the PODEX and SEAC4RS campaigns over the continental USA. Aerosol retrievals performed from RSP measurements show good agreement with ground-based AERONET measurements for aerosol optical depth (AOD), single scattering albedo (SSA) and refractive index. Furthermore, we found that inclusion of shortwave infrared bands (1590 and/or 2250 nm) significantly improves the retrieval of AOD, SSA and coarse mode microphysical properties. However, accuracies of the retrieved aerosol properties do not improve significantly when more than five viewing angles are used in the retrieval.

Temperaturabhängigkeit der statischen Dielektrizitätskonstante und des optischen Brechungsindexes von Flüssigkeiten

1975 ◽  
Vol 30 (3) ◽  
pp. 287-291 ◽  
Author(s):  
I. Gryczyński ◽  
A. Kawski
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Dipole Moment ◽  
Dipole Moments ◽  
Mixed Solvents ◽  
Temperature Changes ◽  
Temperature Dependences ◽  
Solvent Shifts ◽  
Pure And Mixed Solvents ◽  
Good Agreement

A variation of the temperature changes the static dielectric constant (ε) and the refractive index (n) of solvents and, in conjunction with the measurement of solvent shifts of absorption and fluorescence maxima, allows the investigation of dipole moment changes of solutes in the excited state. For this purpose, investigations of the temperature dependences of ε and n of some pure and mixed solvents of different polarities have been made. It is found that the excited dipole moments of indole, 1,2-dimethylindole, 2,3-dimethylindole and tryptophan obtained from the shifts of the fluorescence maxima in mixed solvents at high temperatures are in good agreement with those obtained in other ways.

scholarly journals COMPARISON OF PARTICLE SHAPES OF CONVENTIONALLY GROUND BARITE, CALCITE AND TALC MINERALS BY DYNAMIC IMAGING TECHNIQUE: A REVIEW

2020 ◽  
Vol 5 ◽  
pp. 80-90
Author(s):  
Ugur Ulusoy
Keyword(s):  
Critical Issue ◽  
Dynamic Imaging ◽  
Industrial Minerals ◽  
Grinding Mills ◽  
Conventional Grinding ◽  
Industrial Mineral ◽  
Dynamic Image Analysis ◽  
And Control ◽  
Particle Shapes ◽  
Good Agreement

Shape of particles made by grinding is one of the important measures for determining the utilizations of industrial minerals namely barite, calcite, and talc particles, particularly at production (like coating pigments, paints, rubber and paper) and processing stages (beneficiation by flotation). Therefore, measurement of particle characteristics is a critical issue in the development and control of industrial mineral products in most of the industries for some demanding applications. Ball and rod mills are commonly used as conventional grinding mills to produce a controlled grind size for the flotation circuit in the beneficiation of industrial minerals. Dynamic Image Analysis (DIA) offers reproducible results of a huge number of particles for some industrial minerals namely, barite [1], calcite [2] and talc [3] particles, whose shapes are crucial for some industries utilized as fillers. Thus, this review is about the comparison of shape values in terms of circularity (C) and bounding rectangle aspect ratio (BRAR) determined by the real time DIA. It was found that the shape results of the previous studies for the same samples by SEM measurement [4] were in good agreement with DIA results. It was concluded that the more rounded particles were encountered in the rod milled products for calcite and barite minerals. On the other hand, the more elongated particles were found in the ball milled products for talc mineral. It was attributed to the material type since the same mills were used for all tests. Hence, DIA can be used as a useful tool, which is easy, fast and highly accurate to control the particle shape distributions whether the required powder is fit for use

scholarly journals Model Analysis of 108–76°1

1978 ◽  
Vol 76 ◽  
pp. 354-355
Author(s):  
Bruce Balick ◽  
G.O. Boeshaar
Keyword(s):  
Computer Model ◽  
Galactic Halo ◽  
Line Strength ◽  
Central Star ◽  
Model Analysis ◽  
Homogeneous Sphere ◽  
Plane Parallel ◽  
Atmosphere Model ◽  
Volume Models ◽  
Good Agreement

108–76°1 was discovered by Boeshaar and Bond (1977, Ap. J., 213, 421) to be a member of the galactic halo component. Herein are presente the results of a computer model analysis of these observations and those of Hawley and Miller (this volume). Models producing the 23% of helium in the doubly-ionized state required by the Hell X4686 line strength utilized the 95,000°K, non-gray, spherical atmosphere model of Cassi-nelli (1971, Ap. J., 165, 265) for the central star. Even 100,000°K plane-parallel atmospheres gave less than half the needed He++. The results for model 1 (homogeneous sphere) and model 2 (Gaussian shell) show good agreement with observed fluxes, even for [OH] X3727. The abundance values

scholarly journals Parameter Identification of Tractor-Semitrailer Model under Steering and Braking

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Yiming Li ◽  
Qin Shi ◽  
Duoyang Qiu
Keyword(s):  
Genetic Algorithm ◽  
Field Test ◽  
Test Data ◽  
Performance Testing ◽  
Roll Angle ◽  
Lookup Table ◽  
The Real ◽  
Yaw Rate ◽  
Roll Rate ◽  
Good Agreement

This paper describes a valuable linear yaw-roll tractor-semitrailer (TST) model with five-degree-of-freedom (DOFs) for control algorithm development when steering and braking. The key parameters, roll stiffness, axle cornering stiffness, and fifth-wheel stiffness, are identified by the genetic algorithm (GA) and multistage genetic algorithm (MGA) based on TruckSim outputs to increase the accuracy of the model. Thus, the key parameters of the simplified model can be modified according to the real-time vehicle states by online lookup table and interpolation. The TruckSim vehicle model is built referring to the real tractor (JAC-HFC4251P1K7E33ZTF6×2) and semitrailer (Luyue LHX9406) used in the field test later. The validation of the linear yaw-roll model of a tractor-semitrailer using field test data is presented in this paper. The field test in the performance testing ground is detailed, and the test data of roll angle, roll rate, and yaw rate are compared with the outputs of the model with maps of the key parameters. The results indicate that the error of the tractor’s roll angle and semitrailer’s roll angle between model data and test data is 1.13% and 1.24%, respectively. The roll rate and yaw rate of the tractor and semitrailer are also in good agreement.

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