In 1982, the Belgian Pilots' Guild raised the question of what effect exposure to radar radiation--for example, that encountered in passing a pilot launch's radar--might have on the human body. Recapitulating investigations of this question, this article states that in 25 years of experience with radar, there have been no known incidents of pilots being affected by radar waves. In the future, however, involvement by some pilots with Vessel Traffic Service shore-based radar could affect pilots somewhat differently from limited exposure to pilot launch radar. Pilots who find themselves in new working conditions close to an emitting source should exercise care all times.

About heat waves

these plants can be readily propa gated from seed; some exhibit complex seed dormancies and are more easily propagated by root division or stem cuttings. This article will focus on propagation of wildflowers and grasses using seed, as this is the commonly used, but often misunderstood, method of producing native herbaceous perennials. The methods described herein are based upon our 30 years of experience at Prairie Nursery in propagating a wide variety of native plants from seed. Most native perennials require that their seed be pre-treated to break dormancy prior to seeding. There are four basic types of seed treatments or planting methods that we use to overcome seed dormancy: Dry Stratification: Seed is exposed to freezing temperatures for 30 or more days. Moist Stratification: Seed is mixed with a damp inert substrate and stored in a refrigerated environment at 34-36 degrees Fahrenheit (1-2 degrees Celsius). The seed should not be frozen, as this may damage the cell walls and destroy the seed. Scarification: Seed with hard seed-coats are scratched with sandpaper to allow moisture to penetrate into the seed and initiate the germination process. Hot Water: Seeds that are stimulated to germinate by wildfires are treated with nearboiling water.

전자파 Propagation 개요

In this work, the dual-phase-lag (DPL) heat transfer model is introduced to study the problem of an isotropic generalized thermoelastic medium with an internal heat source that is moving with a con...

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The elastic wave motions for a photothermal medium of a dual-phase-lag model with an internal heat source and gravitational field

In this study, the natural convection boundary layer flow along with inverted cone, magnetic and heat generation on water and ethylene glycol based nanofluids is considered by means of variable wall temperature. Porous medium is also taken into account. The physical problem is first modeled and then the governing equations are transformed into nonlinear ordinary differential equations under the assumptions of the Boussinesq approximation. Analytical solutions of nonlinear coupled equations are obtained by the homotopy analysis method. Correlation of skin friction and heat transfer rate corresponding to active parameters is also presented. Obtained results are illustrated by graphs and tables in order to see the effects of physical parameters.

Magnetohydrodynamic flow of water/ethylene glycol based nanofluids with natural convection through a porous medium

In this problem, we study the effect of variable thermal conductivity, which depend on temperature in the context of Photothermal diffusion (PTD). The PTD process is applied with thermoelasticity theory in chemical action. The model introduced describes the interaction between elastic-thermal-plasma waves, which based on the material properties of semiconductor elastic medium. The Laplace transform is used to solve the governing equations in one dimension of a thin circular plate. Some new constant will be appearing during the theoretical discussion. The mechanical forces and thermal loads are applied on the free surface of semiconductor to obtain the physical fields. The complete solutions in time domain are observed by using a numerical approximation method. The physical fields with some comparsions are presented analytically and graphically.

Effect of Variable Thermal Conductivity during the Photothermal Diffusion Process of Semiconductor Medium

In this article, the novel mathematical model under the effect of Thomson heating of a semi-infinite semiconductor elastic medium is expressed. The thermoelasticity theory is applied in the presence of magnetic field when the medium illuminated by a laser pulse in context of photothermal excitation. The discussions are focused on studying the overlapping between plasma, thermal, electro-magnetic and elastic waves when they propagated in the medium. The two dimensional (2D) deformations is used in the governing equations when the medium is homogenous and isotropic. The charge density of induced electric current is expressed for a time functionally only. The physical fields are obtained when use the normal mode technique with some thermal, mechanical and plasma loads occur at the free surface of elastic semi-infinite semiconductor medium. The numerical calculations of physical field's distributions are discussed and shown graphically under the effect of Thomson parameter.

Response of electromagnetic and Thomson effect of semiconductor medium due to laser pulses and thermal memories during photothermal excitation

Two-Dimensional Problem of Two Temperature Generalized Thermoelasticity with Normal Mode Analysis Under Thermal Shock Problem

A novel model of two-dimensional deformations for two-temperature theory at the free surface under the excitation of thermoelastic wave by pulsed laser for a semi-infinite semiconducting medium is studied. The effect of mechanical force during a photothermal process is investigated. The mathematical methods of the Lord–Shulman (LS includes one relaxation time) and Green–Lindsay (GL with two relaxation times) theories as well as the classical dynamical coupled theory (CD) are used. An exact expression for displacement components, force stresses, carrier density and distribution of temperature are obtained using the harmonic wave analysis. Combinations of two-temperature and photothermal theories are obtained analytically. Comparisons of the results are made between the three theories also. The effects of thermoelectric coupling parameter, two-temperature parameter on the displacement component, force stress, carrier density, and distribution of temperature for silicon (Si) medium have been illustrated graphically. The variations of the considered variables with the horizontal distance have been discussed.

Response of a semiconducting infinite medium under two temperature theory with photothermal excitation due to laser pulses

The dual-phase-lag (DPL) model with two different time translations and Lord–Shulman (LS) theory with one relaxation time are applied to study the effect of hydrostatic initial stress on medium under the influence of two temperature parameter(a new model will be introduced using two temperature theory) and photothermal theory. We solved the thermal loading at the free surface in the semi-infinite semiconducting medium-coupled plasma waves with the effect of mechanical force during a photothermal process. The exact expressions of the considered variables are obtained using normal mode analysis also the two temperature coefficient ratios were obtained analytically. Numerical results for the field quantities are given in the physical domain and illustrated graphically under the effects of several parameters. Comparisons are made between the results of the two different models with and without two temperature parameter, and for two different values of the hydrostatic initial stress. A comparison is ca...

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Papers

Effect of Variable Thermal Conductivity during the Photothermal Diffusion Process of Semiconductor Medium

Response of electromagnetic and Thomson effect of semiconductor medium due to laser pulses and thermal memories during photothermal excitation

Two-Dimensional Problem of Two Temperature Generalized Thermoelasticity with Normal Mode Analysis Under Thermal Shock Problem

Response of a semiconducting infinite medium under two temperature theory with photothermal excitation due to laser pulses

Photothermal waves for two temperature with a semiconducting medium under using a dual-phase-lag model and hydrostatic initial stress