A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Newton’s
Universal Law of Gravitation
Every two bodies
in the universe attract each other with a force which is directly proportional
to the product of their masses and inversely proportional to the square of the
distance between the masses.
Newtonian
Fluids
Fluids which obey
Newton’s law of viscosity are called Newtonian fluids. It is a fluid whose
viscosity doesn’t change with rate of flow.
Newtonian
Telescope
It is telescope
designed by Sir Isaac Newton which uses two mirrors to bring light to a focus.
Light from object being viewed is collected by concave primary mirror and reflected
to a smaller secondary flat plane mirror. The flat mirror is inclined at 45o
to axis of telescope and reflects light to an eye lens which forms an image.
Nicol
Prism
It is a special
kind of a prism made of natural crystal, which is used to obtain plane
polarized light from an un-polarized light and it is also used for analysis of
a given light.
NIM
Layout
A
complete NIM system consists of a NIM crater, NIM bin and NIM modules. A
typical NIM crate has 12 slots for insertion of modules. The communication and
data transfer between the modules is realized through a built-in backplane. One
of the deficiencies of the standard NIM backplane is that it does not have a
digital data bus to allow computer based control. However some of the modern
NIM modules have built-in communication ports, which allow them to be
controlled and read out through a computer. A standard NIM crate has a built-in
power supply that draws power from 110V or 240V AC outlets. Crates having other
specific input voltage ratings are also
available.
The DC voltages are generated within the crate, that is, no extra DC supply
module is needed. The voltages are distributed through the backplane and are
also available in front of the crate for other user-specific requirements.
NIM
Modules
A standard NIM
module has a height of 8.75 inches. The width of the module can be variable but
it must be a multiple of 1.35 inches. The pin layout of a standard NIM module
is a mirror image of the NIM crate connector assignments. Both front and rear
sides of a typical NIM module also contain a number of connectors to facilitate
different I/O operations. Some of the modern NIM modules also contain
communication ports (such as RS232) to allow control and readout through a
computer. These ports are necessary due to unavailability of digital data bus
in NIM crates. As mentioned earlier, NIM modules are well suited for small
scale systems that do not require complicated data handling and control.
NIM
Standard
Nuclear Instrumentation Methods (NIM) is an
old standard that came into effect in 1964. The basic idea behind its
establishment was to introduce standalone and replaceable modules, which could
be combined together to form a complete data acquisition system. The
convenience of using modules interchangeably without disturbing other parts of
the system has been the main source of its widespread use by physicists and
engineers. Even though new standards and modular systems have been introduced
but due to its simplicity of integration and use, NIM is still used in many
places.
Nuclear
Magnetic Resonance (NMR)
Nuclear magnetic resonance (NMR) was first
developed in 1946 by research groups at Stanford and M.I.T., in the USA. NMR is
the phenomenon of absorption of electromagnetic radiation of a specific
frequency by an atomic nucleus that is placed in a strong magnetic field, used
especially in spectroscopic studies of molecular structure and in medicine to
measure rates of metabolism.
Node
Position of a
materialistic wave where positions, displacement, amplitude, velocity and
acceleration are zero, but strain is maximum. Nodes are equivalent in a wave.
No
Equilibrium (Radioactive Decay)
It is condition
of radioactive decay which occurs if the half life of parent is less than the
half life of daughter i.e. activity due to parent nuclide will diminish quickly
as it decays into the daughter. Consequently the net activity will be solely
determined by the activity of the daughter.
Noise
(Sound)
Sound
that produces jarring effect or displeasing effect on ear is called a noise. The
noise succeeds at irregular intervals and there is sudden change in loudness.
or
A
non periodic mechanical disturbance produces sound which appears unpleasant to
ear. It is irregular, non- periodic and discontinuous mechanical substance.
Non-Inertial
Frame of Reference
A reference frame
in which Newton’s laws are not valid in their original forms is called as
non-inertial frame. Any accelerating frame or a rotating frame is non-inertial
frame.
Non-Linear Regression
By nonlinear regression we mean fitting any nonlinear function to the data. This could be a polynomial of the order 2 or more, an exponential, a logarithmic, a combination of these, or some other function. There are different techniques available to handle the nonlinear regression problems but the two most practical and common ones are least squares regression and maximum likelihood regression.
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