Already have an account? Get multiple benefits of using own account!
Login in your account..!
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
LASER BEAM MATERIAL PROCESSING
Light Amplification of Stimulated Emission of Radiation (LASER) is generated when a lasing medium is excited by a source of energy. Gases like argon, helium, neon and carbon dioxide are used as a lasing medium. In addition, Neodymium - Doped Yttrium Aluminium Garnet (Nd:YAG) is the most widely used solid state lasing medium. At the heart of the lasing phenomenon is the ability of photons to stimulate the emission of other photons, each having the same wavelength and direction of travel as the original. According to quantum theory, atoms and molecules have discrete energy levels and can change from one level t o anot her in discontinuous jumps. The energy change required for a jump is provided by the atom's absorption or emission of a burst of electromagnetic radiation. The radiation frequencies involved and the energy spacings between levels are characteristic of the atom, and thus differ from element to element.Generally, atoms or molecules remain quiescent at their lowest energy level, or ground state. But, if these particles are excited into higher energy states by an intense flash of light, an electrical Charge, or other means they will in dropping back to the normal ground state, emit incoherent light in the process. (This is what happens in fluorescent lamps and some types of street lights). In a laser cavity, such emitted photons are trapped between highly polished and parallel mirrors, forcing them to bounce back and Forth in the cavity. Whenever, a photon of any particular wavelength passes close to another excited particle, the second particle will also be stimulated to emit a photon that is identical in wavelength phase and spatial coherence to the first. Both phot ons are now capable of stimulating the emission of more photons like themselves and these too, become part of the growing wave between mirrors. The wave length of each photon is related to its energy E. Lasing begins when enough photons are present and if one of the mirrors is partially transparent, a highly disciplined, intense, now coherent beam is emitted.
Determine elongation because of self weight of tapering rod: Sol.: Take a tapering rod hung vertically and firmly fixed at top position. The rod is of length L tapers unifor
T ype s of Loading: Mainly three types of load acts on any beam; 1. Concentrated load ( or point load) 2. Uniformly distributed load 3. Uniformly varying load
connecting rod AB of length L support a variable compressiv force F .Drive an expression for the moment of F about the crank axis O in the term of F L r and angle
Main characteristics of couple: Sol.: The main characteristics of couple 1. The algebraic sum of the forces, having the couple, is zero. 2. The algebraic sum of moment
In class, we derived and solved a model of a non-isothermal, insulated, CSTR with an exothermic reaction (model6.m). We want to derive and solve a very similar model of a system wi
Non-linear Sweep In non-linear sweep, the path is a curve described by a higher-order equation (quadratic, cubic or higher)
How is gas cutting torch different from the gas welding torch .explain
test test teste teste teste tester
SAFETY IN TIG WELDING-Radiation Energy Hazard Radiant energy may cause injury to the welder in two areas, eye and the skin. Any personnel, whether the welder, inspection person
Q. Seismic Loads For Structure-Mounted Equipment? For equipment mounted in a structure above grade, the governing equation for seismic force is: F p = A v C c Pa c W c , wh
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd