S.D tutorials

  WATER: An important cause of the ill health in underdeveloped countries is the lack of safe drinking water. It should be free from pathogenic agents and harmful chemical substances ,pleasant taste and usable for domestic purpose. An average daily supply of 150-200 liters per head is considered the optimum quantity. Sources of water supply: The two important consideration for selecting a proper source are: (a) Quality of water must be acceptable (b) Quantity must be enough to meet the present requirements Three main sources  of  water are 1. Rain water 2. Surface water 3.Ground water Rain water: Rain water that sinks into the ground forms ground water, and that runs off to form streams,rivers and tanks. Surface water:  The surface water sources include   (a) Impounding Reservoirs:       These are artificial lakes constructed usually of masonry in which large quantities of surface water is stored.      (b) Rivers: Many rivers provide a dependable source of water. The main drawback of r

 Rheology: Defination:  The term  "Rheology " derived from the Greek words, Rheo means "to flow" and logos means "science"  Rheology can be defined as the science concerened with the deformation of matter under the influence of stress,which may be applied perpendicularly to the surface of body,tangential to the surface of body or at any other angle to the surface of body. The result of application of a stress may be divided into two types:         (i)Elastic deformation: It is a reversible process ,deformation is recoverable when the body returns to its original position.         (ii) Plastic deformation: It is a irreversible deformation, The work spent for the deformation is dissolute as heat. Flow is dived into two types (i) Newtonian: Liquids which follow Newton's law of viscous flow are known as newtonian liquid. example: water, true solution,dilute suspensions (ii) Non-Newtonian: Liquids which does not follow Newton's law is called as non-newt