Physics has an important role in our life. Without physics and the work of
physicists, our modern life would not exist. Using physics, people created machines,
instruments and some different divices from the crudest to the most modern aspect.
Techology is developed more rapidly, more modern day by day.
Moreover, all other natural sciences- example chemistry, biology, medicinedepend
upon physics for the foundations of their knowledge.
This thesis presents time-resolved measurements of the spin evolution of transient carrier populations in III-V quantum wells. Non-equilibrium distributions of spin polarisation were photoexcited and probed with picosecond laser pulses in three samples; a high mobility modulation n-doped sample containing a single GaAs/AlGaAs quantum well, an In0.11Ga0.89As/GaAs sample containing three quantum wells and, a multi-period GaAs/AlGaAs narrow quantum well sample.
An equation is a statement of equality: Whatever is on the left-hand side of any equation is equal to whatever is
on the right-hand side. The symbols in an algebraic equation usually cannot have arbitrary values if the equality
is to hold. To solve an equation is to find the possible values of these symbols. The solution of the equation
5x − 10 = 20 is x = 6 because this is the only value of x for which this equation is a true statement.
The algebraic procedures that can be used to solve an equation are all based on the principle that any
Microelectromechanical systems (MEMS) have played an increasingly important
role in sensor and actuator applications. And its key contribution is that it has enabled
the integration of multi-components (i.e., electronics, mechanics, fluidics and etc) on a
single chip and their integration has positive effects upon performance, reliability and
cost. Compared to conventional electrostatic, thermal or magnetic actuating schemes,
piezoelectric MEMS inkjet has the advantages of lower power consumption, lower
voltage operation and relatively larger driving force....
Infrared radiation is a type of electronmagnetic radiation (a wave with electricity) . The wave is longer than light which humans can see and shorter than microwaves. • The name means "below red". The word "Infrared" is from the Latin infra ("below") and red, which has the longest wave for light.