scholarly journals Laboratory Results on Polarization Properties of Elongated Particles and Comparisons to Dust in the Tail of Comet Ikeya-Seki (1965 VIII)

1985 ◽  
Vol 85 ◽  
pp. 227-230
Author(s):  
Bo.Å.S. Gustafson
Keyword(s):  
Particle Shape ◽  
Degree Of Polarization ◽  
Optical Polarization ◽  
Laboratory Measurements ◽  
Scattering Angle ◽  
Steep Gradient ◽  
Laboratory Results ◽  
Dust Tail ◽  
Polarization Characteristics

AbstractData obtained through microwave analog measurements are used to compare optical polarization characteristics of silicate particles ranging in shape from spheroids and cylinders to chains of spheres. It is confirmed that the dependence of the degree of polarization on scattering angle is a powerful indicator of particle shape. The reversal and steep gradient in the degree of polarization found by Weinberg and Beeson (1976a,b) in the dust tail of comet Ikeya-Seki (1965 VIII) is suggestive of laboratory measurements corresponding to 1.6 μm long, 0.4 μm in diameter silicate cylinders.

The Polarization Properties Research of Atmospheric Based on Actual Weather Conditions

2014 ◽  
Vol 556-562 ◽  
pp. 933-936
Author(s):  
Fei Zhang ◽  
Xiao Ping Du ◽  
Shen Wang
Keyword(s):  
Rayleigh Scattering ◽  
Weather Conditions ◽  
Mie Scattering ◽  
New Method ◽  
Degree Of Polarization ◽  
Scattering Angle ◽  
Polarization Characteristics ◽  
Simulation Results

A new method to calculate the polarization properties of the atmosphere by combining the Rayleigh scattering and Mie scattering is proposed in this paper. We inversed the values of the required data by experiment and simulated of the atmosphere polarization characteristics under the same conditions. The simulation results show that the proposed method can accurately describe the variation of the atmosphere polarization properties. Besides, the results show such variation: in the same weather conditions, the degree of polarization is gradually increased while scattering angle is gradually increased as 90°; in the same detect conditions, the degree of polarization decreases with the deteriorating weather conditions.

Quantities Directly Measurable by Scattering

2018 ◽  
Author(s):  
Eaton E. Lattman ◽  
Thomas D. Grant ◽  
Edward H. Snell
Keyword(s):  
Molecular Weight ◽  
Particle Shape ◽  
Particle Surface ◽  
Scattering Data ◽  
Radius Of Gyration ◽  
Particle Volume ◽  
Particle Surface Area ◽  
Scattering Angle ◽  
Particle Dimension ◽  
Maximum Particle

In this chapter we note that solution scattering data can be divided into four regions. At zero scattering angle, the scattering provides information on molecular weight of the particle in solution. Beyond that, the scattering is influenced by the radius of gyration. As the scattering angle increases, the scattering is influenced by the particle shape, and finally by the interface with the particle and the solution. There are a number of important invariants that can be calculated directly from the data including molecular mass, radius of gyration, Porod invariant, particle volume, maximum particle dimension, particle surface area, correlation length, and volume of correlation. The meaning of these is described in turn along with their mathematical derivations.

scholarly journals Optical polarization characteristics of semipolar (303¯1) and (303¯1¯) InGaN/GaN light-emitting diodes

2012 ◽  
Vol 21 (S1) ◽  
pp. A53 ◽  
Author(s):  
Yuji Zhao ◽  
Qimin Yan ◽  
Daniel Feezell ◽  
Kenji Fujito ◽  
Chris G. Van de Walle ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Optical Polarization ◽  
Light Emitting ◽  
Polarization Characteristics

scholarly journals Reducing Drag and Oscillation of Spheres Used for Buoyancy in Oceanographic Moorings

2008 ◽  
Vol 25 (10) ◽  
pp. 1823-1833 ◽  
Author(s):  
Jane Hurley ◽  
Brad de Young ◽  
Christopher D. Williams
Keyword(s):  
Drag Force ◽  
Laboratory Measurements ◽  
Dynamical Calculation ◽  
Laboratory Results ◽  
Drag And Lift ◽  
Eddy Shedding

Abstract Numerical and laboratory results of the drag characteristics are presented for different configurations of an underwater buoyancy package. It is shown that the drag and oscillation of an underwater sphere can be reduced substantially with the addition of a shaped cowling. The influence of several different cowling shapes on the drag and lift are determined. The results from a numerical fluid dynamical calculation are compared and laboratory measurements are scaled. Both the dynamic and static components of drag and lift are presented. The drag force for an underwater sphere can be reduced by more than 80% for a full teardrop-shaped cowling. A truncated teardrop, more practical for real applications, will still reduce the drag by 60%–70%. In addition to the drag, the amplitude of oscillations driven by eddy shedding is similarly reduced.

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