Electromagnetic behavioral responses

Fabre tested this hypothesis and subsequently rejected the idea that electromagnetic radiation was involved in the sexual communication systems of moths however he remained skeptical of the involvement of the sense of smell. Sixty years later the case for smell was finally settled when German chemists, led by A. Butenandt (3-5), were the first to isolate, identify, and synthesize an insect sex pheromone, that of the female silkworm (Bombyx morl). They found that the compound responsible for eliciting sexual behavior from the male moth was ( E, Z)-10,12-hexadecadien-l-ol. 

The results obtained from R6G molecules adsorbed on gold particles also revealed various dynamic spectroscopic features like fluctuations in intensity and even sporadically slight changes in spectral position. As the R6G concentration is relatively high compared to the amount of gold nanoparticles present and thermal effects can be excluded, the only possible explanation for the dynamic behavior seems to be fluctuations of the enhanced electromagnetic field [43]. Additionally, spatial and time-dependent changes in the orientation of the adsorbed molecule in the field may be also responsible for the fluctuations. 

In the last 40 years, techniques to directly measure surface forces and force laws (force vs. separation distance between surfaces) have been developed such as the surface forces apparatus (SFA) [6] and AFM. Surface forces are responsible for the work required when two contacting bodies (such as an AFM tip in contact with a solid surface) are separated from contact to infinite distance. Although the physical origin of all relevant surface forces can be derived from fundamental electromagnetic interactions, it is customary to group these in categories based on characteristic features that dominate the relevant physical behavior. Thus, one speaks of ionic (monopole), dipole—dipole, ion—dipole interactions, electrostatic multipole forces (e.g., quadrupole), induced dipolar forces, van der Waals (London dispersive) interactions, hydrophobic and hydrophilic solvation, structural and hydration forces,... 

The free electric charges - electrons and ions - make plasma electrically conductive (sometimes more than gold and copper), internally interactive, and strongly responsive to electromagnetic fields. Ionized gas is usually called plasma when it is electrically neutral (i.e., electron density is balanced by that of positive ions) and contains a significant number of the electrically charged particles, sufficient to affect its electrical properties and behavior. In addition to being important in maty aspects of our daily fives, plasmas are estimated to constitute more than 99% of the visible universe. 

Principle Is the fundamental law that allows the development of a quantitative relation of the state variables. It governs behavior as the relationships among a set of state variables. For example, in Fig. 1, two possible principles are electromagnetism raling the operation of the electric motor and solid mechanics ruling the function of the crank mechanism. Behavior Represents the response of the structure when it receives stimuU. Since the structure is represented by state and structure variables, behaviors are quantified by the values of these variables. In the case presented in Fig. 1, the two behaviors are Generate torque and Convert torque into force. Function It is about the usefulness of a system. For example, in Fig. 1, one possible function of this system is to compress gas. 

In the broadest sense, optofluidics involves the manipulation of the local optical properties of a system using fluids and flow behavior and, conversely, the manipulation of fluids and particles within a flow through optical forces. The latter is inherently concerned with both the optical and thermophysical properties of the fluid and the dynamics of how both the electromagnetic and flow fields change in response to external stimuli. Optical forces used to manipulate fluid and particle behavior can arise either from focused beams in fi-ee space or from guided... 

These experimental findings for low-frequency electromagnetic response are in contrast with the expectations for the Anderson IMT [99] in which electronic behavior is controlled by disorder. In the dielectric phase, electrons are bound by fluctuations of the random potential. On the metallic side of the transition, free carriers have short scattering times. In the metallic phase near the transition s is positive because the disorder causes dynamic polarization due to slowing diffusion due to localization effects. When approaching the IMT transition the localization effects increase and s diverges (dielectric catastrophe [120]). 

The emphasis to this point has been on the response of polymer materials to mechanical stresses. There are several other important external effects that are important to the behavior of plastic parts. The effects of heat, electrical Helds, and electromagnetic radiation are frequently important in the design of plastic parts. Since each of these effects will clarify the way in which polymers behave, they will be briefly covered as background for the design relationships to be developed in the following chapters. 

When materials are exposed to electromagnetic radiation, it is sometimes important to be able to predict and alter their responses. This is possible when we are familiar with their optical properties and understand the mechanisms responsible for their optical behaviors. For example, in Section 21.14 on optical... 

Optical property refers to a material s response to exposure to electromagnetic radiation and, in particular, to visible light. This chapter first discusses some of the basic principles and concepts relating to the nature of electromagnetic radiation and its possible interactions with solid materials. Then it explores the optical behaviors of metallic and nonmetal-lic materials in terms of their absorption, reflection, and transmission characteristics. The final sections outline luminescence, photoconductivity, and light amplification by stimulated emission of radiation (laser), the practical use of these phenomena, and the use of optical fibers in communications. 

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