On the transmission of data packets through fiber-optic cables of uniform index

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sujit K. Bose
Keyword(s):  
Phase Velocity ◽  
Maxwell Equations ◽  
Fiber Optic ◽  
Experimental Measurements ◽  
Property A ◽  
Wave Groups ◽  
Data Packets ◽  
Tail Distribution ◽  
Poisson Arrivals ◽  
Frequency Phase

Abstract The treatment of Maxwell equations show that propagating wave of packets in fiber-optic cables is dispersive, propagating in groups, such that group velocity along certain curves in the frequency-phase velocity diagrams vanishes. It is suggested that stalling of wave groups is responsible, for bursting propagation observed in experimental measurements, causing some delay in transmission. The dispersion equations developed here, are different from those given in texts that are based on “weakly guiding approximation”. The queue of such data packets arriving at a router station is found to have a “raised tail” distribution unlike that of Poisson arrivals. For accounting the property, a Mittag–Leffler function distribution (MLFD) of probability is used following a modification of that for a Poisson process, the tail raising is shown to cause delay in transmission, and its estimate is analysed based on the theory.

scholarly journals Effect of Rotation on Wave Propagation in Hollow Poroelastic Circular Cylinder

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
S. M. Abo-Dahab ◽  
A. M. Abd-Alla ◽  
S. Alqosami
Keyword(s):  
Wave Propagation ◽  
Circular Cylinder ◽  
Phase Velocity ◽  
Frequency Equation ◽  
Wave Number ◽  
Elastic Behavior ◽  
Hollow Circular Cylinder ◽  
Poroelastic Material ◽  
Phase Velocity And Attenuation ◽  
Frequency Phase

The objective of this paper is to study the effect of rotation on the wave propagation in an infinite poroelastic hollow circular cylinder. The frequency equation for poroelastic hollow circular cylinder is obtained when the boundaries are stress free and is examined numerically. The frequency, phase velocity, and attenuation coefficient are calculated for a pervious surface for various values of rotation, wave number, and thickness of the cylinder which are presented for nonaxial symmetric vibrations for a pervious surface. The dispersion curves are plotted for the poroelastic elastic behavior of the poroelastic material. Results are discussed for poroelastic material. The results indicate that the effect of rotation, wave number, and thickness on the wave propagation in the hollow poroelastic circular cylinder is very pronounced.

Optical Measurements of Shrinkage in UV-Cured Adhesives

2002 ◽  
Vol 124 (4) ◽  
pp. 352-354 ◽  
Author(s):  
A. J. Hudson ◽  
S. C. Martin ◽  
M. Hubert ◽  
J. K. Spelt
Keyword(s):  
Optical Method ◽  
Fiber Optic ◽  
Uv Light ◽  
Optical Measurements ◽  
Volumetric Shrinkage ◽  
Experimental Measurements ◽  
Curing Conditions ◽  
Curing Methods ◽  
Controlled Exposure ◽  
Selection Of

This paper describes an optical method that has been developed to accurately measure shrinkage during the cure of adhesives treated with UV light. The experiment was designed to measure changes in the volume of very small quantities of material appropriate to uses in the fiber-optic and micro-electronic industries. A spot-curing device (EFOS Inc.) was used to deliver a controlled exposure of UV-light with a known distribution of wavelengths to the sample. The results indicate that reproducible values for the volumetric shrinkage can be achieved using spot-curing methods. The technique described in this paper, combined with other experimental measurements under development, will assist in the selection of the appropriate adhesive for specific applications and the curing conditions needed to optimize its final properties.

scholarly journals Phase Velocity and Attenuation of Longitudinal Shear Vibrations of Hollow Poroelastic Cylinders

2014 ◽  
Vol 19 (2) ◽  
pp. 337-346
Author(s):  
S. Ahmed Shah ◽  
S. Javvad Hussaini
Keyword(s):  
Cylindrical Shell ◽  
Phase Velocity ◽  
Longitudinal Shear ◽  
Frequency Equation ◽  
Circular Cylinders ◽  
Physical Parameters ◽  
Flexural Mode ◽  
Second Mode ◽  
Phase Velocity And Attenuation ◽  
Frequency Phase

Abstract The present paper is devoted to the study of phase velocity and attenuation of longitudinal shear vibrations of hollow poroelastic circular cylinders in the presence of dissipation. The explicit expressions for phase velocity and attenuation of longitudinal shear vibrations are derived. The frequency equation of longitudinal shear vibrations and modes obtained in a previous paper are used to compute the phase velocity and attenuation for different dissipations for thin and thick poroelastic cylindrical shells and poroelastic solid cylinder. The physical parameters of sandstone saturated with kerosene and sandstone saturated with water are used for the purpose of computation. It is found that the phase velocity is linear beyond certain frequency. Phase velocity is smaller for a typical anti-symmetric mode compared to the flexural mode. It is greater for the second mode than that of the first mode. Also the phase velocity is larger for a thin poroelastic cylindrical shell than that of a thick poroelastic cylindrical shell. The same is true for attenuation also. Attenuation is very high for the considered dissipations and it increases with the increase in dissipation.

A note on breaking waves

1988 ◽  
Vol 419 (1857) ◽  
pp. 323-335 ◽  
Keyword(s):  
Phase Velocity ◽  
Gravity Waves ◽  
Turbulent Mixing ◽  
Wave Breaking ◽  
Richardson Number ◽  
Breaking Waves ◽  
Internal Gravity Waves ◽  
Time Interval ◽  
Wave Groups ◽  
Surface Gravity Waves

Some simple general properties of wave breaking are deduced from the known behaviour of surface gravity waves in deep water, on the assumption that breaking occurs in association with wave groups. In particular we derive equations for the time interval, ז, between the onset of breaking of successive waves: ז ═ T / |1 – ( c ⋅ c g )/ c 2 |, and for the propagation vector c b (referred to as the ‘wave-breaking vector’) of the position at which breaking, once initiated, will proceed: c b ═ c (1 – c ⋅ c g / c 2 )+ c g . Here c is the phase velocity, and c g the group velocity, of waves of period T . Interfacial waves, internal gravity waves, inertial waves and planetary waves are considered as particular examples. The results apply not only to wave breaking, but to the movement of any property (e. g. fluid acceleration, gradient Richardson number) that is carried through a medium in association with waves. One application is to describe the distribution, in space and time, of regions of turbulent mixing, or transitional phenomena, in the oceans or atmosphere.

Analytical solutions of thermo-piezoelectric interactions in a solid fiber of polygonal cross-sections immersed in fluid

2018 ◽  
Vol 14 (3) ◽  
pp. 431-456
Author(s):  
Rajendran Selvamani
Keyword(s):  
Mathematical Model ◽  
Phase Velocity ◽  
Cross Sections ◽  
Analytical Solutions ◽  
Fourier Expansion ◽  
Transversely Isotropic ◽  
Cross Sectional ◽  
Content Type ◽  
Phase Velocity And Attenuation ◽  
Frequency Phase

Purpose The purpose of this paper is to study the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid using the Fourier expansion collocation method. Design/methodology/approach A mathematical model is developed for the analytical study on a transversely isotropic thermo-piezoelectric polygonal cross-sectional fiber immersed in fluid using a linear form of three-dimensional piezothermoelasticity theories. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been analyzed numerically by using the Fourier expansion collocation method (FECM) at the irregular boundary surfaces of the polygonal cross-sectional fiber. The roots of the frequency equation are obtained by using the secant method, applicable for complex roots. Findings From the literature survey, it is evident that the analytical formulation of thermo-piezoelectric interactions in a polygonal cross-sectional fiber contact with fluid is not discussed by any researchers. Also, in this study, a polygonal cross-section is used instead of the traditional circular cross-sections. So, the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid are studied using the FECM. The dispersion curves for non-dimensional frequency, phase velocity and attenuation coefficient are presented graphically for lead zirconate titanate (PZT-5A) material. The present analytical method obtained by the FECM is compared with the finite element method which shows a good agreement with present study. Originality/value This paper contributes the analytical model to find the solution of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid. The dispersion curves of the non-dimensional frequency, phase velocity and attenuation coefficient are more prominent in flexural modes. Also, the surrounding fluid on the various considered wave characteristics is more significant and dispersive in the hexagonal cross-sections. The aspect ratio (a/b) of polygonal cross-sections is critical to industry or other fields which require more flexibility in design of materials with arbitrary cross-sections.

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