radiation so what is radiation and how it’s used in controlling microbes
Energy is transmitted through space or through a material medium is generally called as radiation. The major types of radiations are electromagnetic radiation, acoustic and particle radiation. The electromagnetic radiations are the most significant eg. light and X- rays.
Electromagnetic radiation has the dual properties of a continuous wave phenomenon and the discontinuous particle phenomenon. The particle are the packets or the quanta of the energy are sometimes called photons, which vibrate at different frequency. Radiations can also be described by its wavelength ƛ it is measured in angstrom where 1µm = 10,000 Å
Ionising radiations – gamma rays and x-rays which have energies of more than 10eV , are called ionizing radiations. They have great penetrating power and have enough energy to pull electrons away from the molecules and ionize them. When they pass through the cell they form free hydrogen and hydroxy radicals and some peroxides , which react with the cellular constituents and cause damage to cells. Since the damage is produced in a wide variety of the constituents, the ionizing radiation are non-specific in their effects. Their damaging effects are linked to the oxygen. One main assumptions is that the free radicals oxidize vital materials in the cell. Although they have great penetration power and toxicity, they are impractical for the purpose of sterilisation because
- Their large scale production is expensive
- Their efficient utilisation is difficult, since radiations are given off in all the directions from their point of origin
- Their continuous use is hazardous to operators.:
Electricity :
Electric current of varying voltages, intensity , and periods of action have been investigated as a means to destroy the microorganisms. Equipments for the use of the electricity has been designed and used for the pasteurization of milk and fruits juices and for disinfection of water , sewage etc. the killing effect is due to :
- Heat produced by resistance to the passage of the current
- Formation of germicidal material like ozone , and chlorine by the action of current upon the suspending fluid
to be continued……..