VISHWAKARMA INSTITUTE OF TECHNOLOGY

  Nanotechnology Introduction Nanotechnology is the design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular, and macromolecular scale) that produces structures, devices, and systems with at least one novel/superior characteristic or property.  A nanometer is one-billionth of a meter: ten times the diameter of a hydrogen atom. The diameter of a human hair is, on average, 80,000 nanometers. At such scales, the ordinary rules of physics and chemistry no longer apply. For instance, materials' characteristics, such as their colour, strength, conductivity and reactivity, can differ substantially between the nanoscale and the macro. Carbon 'nanotubes' are 100 times stronger than steel but six times lighter. Nanotechnology as defined by size is naturally broad, including fields of science as diverse as  surface science ,  organic chemistry ,  mol...

                                                           Higher Pairs INTRODUCTION: In The higher pair, only one point or line are responsible to form a joint between two links. The elements of higher pair must have curve in its shape. These joints are found in the cylinders or spheres of equal or different radius which have their axis parallel to each other. A cylinder or sphere lying on a flat surface has a point Contact and makes a higher pair. The relative motion of cam and follower makes a point Contact between them. The point of contact between two involute gear meshing makes a higher pair. These are some basic examples to explain the higher pair better.   When the two elements of a pair have a line or point contact when relative motion takes place and the motion between the two elements is partly turning and partly sliding, t...