We have known the close connection between changing eletric fields
and magnetic fields. They can create each other and form a system of
Electromagnetic fields can propagate in the space (vacuum or material
environment). We call them electromagnetic waves. They play a very
important role in science and technology.
This book is concerned with Ultra-Low-Frequency (ULF)-electromagnetic
waves observed on the Earth and in Space. These are so-called geomagnetic
variations or pulsations. Alfv´en’s discovery related to the influence of the
strong magnetic field on the conducting fluids (magnetohydrodynamics) led
to development of the concept that the ULF-waves are magnetospheric magnetohydrodynamic
MHD-waves at their propagation gather information about the magnetosphere,
ionosphere, and the ground. There are two applied aspects based on
using the ULF electromagnetic oscillations.
The purpose of this monograph is to formulate a quantitative and self-consistent theoretical
approach to wave–particle interactions occurring in space plasmas, and present
a logical development of the subject. In the Earth’s magnetosphere, Nature has given
us a plasma laboratory that is accessible to observations made by radio, magnetic and
electric instruments on the ground, and a great variety of instruments aboard rockets
and Earth-orbiting satellites. Spacecraft are making similar observations in the more
distant solar system.
This book deals with topics in atomic and molecular structure and
dynamics that are important to astronomy. Indeed, the topics selected
are of central interest to the field of astronomy, many having been initiated
by the needs of understanding worlds other than ours. Except
for some lunar surface material returned by the Apollo missions, and
material naturally delivered to us by cosmic rays, comets, and meteors,
our only access to the other worlds of our astronomical Universe is
through our observations of electromagnetic radiation from them.
Inductive proximity sensors are widely used in various applications to detect
metal devices. They consist of an oscillator, trigger, and switching amplifier. If a
metal object enters the electromagnetic field of the oscillator coil, eddy currents are
induced in this coil which change the amplitude of oscillation, which causes the trigger
stage to trip and the semiconductor output stage to switch.
Interference and diffraction of light are arguments for wave
charactiristics of light.
We know that there are two types of wave processes: transverse &
longitutional waves →to what are light waves belong ?
Study of polarization of light makes clear that
This conclusion is in according to the concept that light waves are
electromagnetic waves with a definte band of frequencies. Recall that
electromagnetic waves are transervse waves in which e-vectors &
m-vectors oscillate in such follwing directions...
In this book, the performance characteristics of distributed feedback semiconductor laser diodes and optical tunable ﬁlters based on DFB laser structures have been investigated. As discussed in Chapter 1, these lasers can be used as optical sources and local oscillators in coherent optical communication networks, in which a stable single mode (in both the transverse plane and the longitudinal direction) and narrow spectral linewidth become crucial.