scholarly journals On the Boundary Intensities in a Plane Parallel Slab With Linearly Varying Refractive Index

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Vital Le Dez ◽  
Hamou Sadat
Keyword(s):  
Refractive Index ◽  
Diffuse Reflection ◽  
Exact Expression ◽  
Plane Parallel ◽  
Semitransparent Medium ◽  
The One

An exact expression of the outgoing boundary intensities in the case of a gray nonscattering semitransparent medium (STM) confined in a plane parallel slab with a refractive index linearly depending on the position is proposed. It is shown that directly using the diffuse reflection law gives in a much easier way exactly the same result as the one obtained with the pseudosource method.

Stress Whitening in Polypropylene. I. Light Scattering Theory and Model Experiments

1995 ◽  
Vol 60 (11) ◽  
pp. 1875-1887 ◽  
Author(s):  
Jaroslav Holoubek ◽  
Miroslav Raab
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Incident Light ◽  
Polymeric Materials ◽  
Wavelength Dependence ◽  
Theoretical Background ◽  
Surrounding Matrix ◽  
Embedded Particles ◽  
The One ◽  
Stress Whitening

Theoretical background for an optical method is presented which makes it possible to distinguish unambiguously between voids and particles as light scattering sites in polymeric materials. Typical dependences of turbidity as a function of diameter of scattering elements, their volume fractions and also turbidity curves as a function of the wavelength of the incident light were calculated, based both on the Lorenz-Mie theory and the fluctuation theory. Such dependences calculated for polypropylene-containing voids on the one hand and particles, differing only slightly from the surrounding matrix in their refractive index, on the other hand, are markedly different. The most significant results are: (i) Turbidity is at least by two orders of magnitude larger for voids in comparison to embedded particles of ethylene-propylene (EPDM) rubber of the same size, concentration and at the same wavelength. (ii) The wavelength dependence of turbidity for EPDM particles and the inherent refractive index fluctuations in the polypropylene matrix is much steeper as compared to voids for all considered diameters (0.1-10 μm). Thus, the nature of stress whitening in complex polymeric materials can be determined from turbidity measurements.

scholarly journals On the influence of their state in solution on the absorption spectra of dissolved dyes

1909 ◽  
Vol 82 (554) ◽  
pp. 256-270 ◽  
Keyword(s):  
Refractive Index ◽  
Absorption Spectra ◽  
Organic Solvents ◽  
Absorption Maximum ◽  
Previous Investigation ◽  
Cyanine Dyes ◽  
Water Band ◽  
The One

In a previous investigation of the absorption spectra and sensitising properties of some iso cyanine dyes,* the influence of the solvent was examined and it was found that the absorption maximum was shifted toward the red as the refractive index of the solvent increased. This is in accordance with Kundt’s law. The absorption in water, however, differs markedly from that in organic solvents. In the latter the spectrum consists of a prominent band in the orange and a half-shade nearer the blue. In water this half-shade has become a separate band comparable in intensity with the orange. Absorption curves in alcohol and water are shown. It is convenient to term the band near the red the β-(organic) band, the one nearer the blue the α -(water) band. It appeared desirable to investigate this difference further.

Reflection and transmission coefficients in plane-parallel layers with refractive-index mismatch

1992 ◽  
Vol 31 (1) ◽  
pp. 106 ◽  
Author(s):  
Leonard I. Grossweiner ◽  
James L. Karagiannes ◽  
Linda Ramball Jones ◽  
Porter W. Johnson
Keyword(s):  
Refractive Index ◽  
Reflection And Transmission Coefficients ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Plane Parallel

scholarly journals ELECTRODYNAMICS IN A BACKGROUND CHIRAL FIELD

2011 ◽  
Vol 26 (38) ◽  
pp. 2879-2887
Author(s):  
F. T. BRANDT ◽  
D. G. C. MCKEON ◽  
A. PATRUSHEV
Keyword(s):  
Vector Field ◽  
Euclidean Space ◽  
Effective Action ◽  
Exact Expression ◽  
Two Dimensions ◽  
Perturbative Expansion ◽  
Dimensional Euclidean Space ◽  
Chiral Field ◽  
Axial Field ◽  
The One

We consider the one-loop effective action in four-dimensional Euclidean space for a background chiral field coupled to a spinor field. It proves possible to find an exact expression for this action if the mass m of the spinor vanishes. If m does not vanish, one can make a perturbative expansion in powers of the axial field that contributes to the chiral field, while treating the contribution of the vector field exactly when it is a constant. The analogous problem in two dimensions is also discussed.

Simulation of the one-phase Stefan problem in a layer of a semitransparent medium

2015 ◽  
Vol 24 (2) ◽  
pp. 123-138 ◽  
Author(s):  
N. A. Rubtsov ◽  
N. A. Savvinova ◽  
S. D. Sleptsov
Keyword(s):  
Stefan Problem ◽  
Semitransparent Medium ◽  
The One

Dependence of stress-optical coefficients on the mechanical and optical properties of polymers

1973 ◽  
Vol 8 (4) ◽  
pp. 267-276 ◽  
Author(s):  
P S Theocaris
Keyword(s):  
Mechanical Properties ◽  
Refractive Index ◽  
Optical Properties ◽  
Internal Structure ◽  
The Other ◽  
Linear Region ◽  
Non Linear ◽  
Linear Viscoelastic ◽  
Linear Viscoelastic Behaviour ◽  
The One

The internal structure of the stress-optical coefficients, as they are related to various direct interferometric methods, has been analysed and the nature of their components studied. It is shown that the stress-optical coefficients are composed of two parts. The one part depends on the variation of the mechanical properties; the other is related to the variation of the refractive index of the polymer. The influence of the mechanical properties is considerable and comparable to the influence of the optical properties. The study of the mechanical and optical contributions to the values of the stress-optical coefficients included not only the linear, but also the non-linear viscoelastic behaviour of the polymers. It is concluded that the corresponding limits of linearity of these coefficients do not coincide. Furthermore, the influence of the mechanical properties on the stress-optical coefficients is increasing relatively to the influence of the optical properties in the non-linear region.

scholarly journals CAMERA CONSTANT IN THE CASE OF TWO MEDIA PHOTOGRAMMETRY

2015 ◽  
Vol XL-5/W5 ◽  
pp. 1-6 ◽  
Author(s):  
P. Agrafiotis ◽  
A. Georgopoulos
Keyword(s):  
Refractive Index ◽  
Camera Calibration ◽  
Focal Length ◽  
Calibration Procedure ◽  
Water Salinity ◽  
Clean Water ◽  
Object Distance ◽  
Calibration Methods ◽  
The One ◽  
Probable Relation

Refraction is the main cause of geometric distortions in the case of two media photogrammetry. However, this effect cannot be compensated and corrected by a suitable camera calibration procedure (Georgopoulos and Agrafiotis, 2012). In addition, according to the literature (Lavest et al. 2000), when the camera is underwater, the effective focal length is approximately equal to that in the air multiplied by the refractive index of water. This ratio depends on the composition of the water (salinity, temperature, etc.) and usually ranges from 1.10 to 1.34. It seems, that in two media photogrammetry, the 1.33 factor used for clean water in underwater cases does not apply and the most probable relation of the effective camera constant to the one in air is depending of the percentages of air and water within the total camera-to-object distance. This paper examines this relation in detail, verifies it and develops it through the application of calibration methods using different test fields. In addition the current methodologies for underwater and two-media calibration are mentioned and the problem of two-media calibration is described and analysed.

Perturbation Method for Boundary S-Matrix in 2D Quantum Field Theory

1997 ◽  
Vol 12 (38) ◽  
pp. 2951-2962 ◽  
Author(s):  
Nadia Topor
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Free Parameter ◽  
Exact Expression ◽  
Quantum Field ◽  
Boundary Interaction ◽  
S Matrix ◽  
Sine Gordon Model ◽  
The One ◽  
Perturbative Result

We develop a perturbation theory for evaluating the boundary S-matrix in 2D quantum field theory. We apply this approach to calculate the one-loop boundary S-matrix for the elementary particle of the sine–Gordon model with a boundary interaction. Our perturbative result agrees with the exact expression of the S-matrix conjectured by Goshal; it also allows us to derive the perturbative relation between the parameter ϑ in the S-matrix and the free parameter M in the boundary action, in the particular case in which its other free parameter φ0 is zero.

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