Ergonomics

Meaning of ‘Ergons’ is ‘work’ and meaning of ‘Nomos’ is ‘natural laws’. Thus Ergonomics is the study of the relationship between man and his working environments.  An Ergonomist should have the knowledge of an engineer, psychologist, biometrician, anatomist, physiologist and anthropologist. The main objective of ergonomics study is optimizing the integration of man and machine and thus increasing the work rate, efficiency and accuracy. Here first stage involves the design of working environment suited to various requirements of the worker. In the second stage, equipments, machinery and controls are designed in such a way that the mental and physical strains of workers are decreased.  The third stage involves the design of a conductive environment for the smooth execution of tasks. Ergonomics is applied in the design of working environments, work place and some other areas. In the design of working environments and workplace, different factors which are worth taking care of are lighting, temperature, humidity, fresh air circulation, noise, bad odor, smokes, fumes, furniture placement, machine tools placement etc. Ergonomics is also applied in studies related to fatigue.

Highway engineering

Highways gained importance recent days due to the great advancement in vehicle manufacturing technology which helps to achieve very high speeds. But to maintain very high speeds, highways should be wide and damage free. Aggregate crushing value which gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load should be less for better results. A quantity which gives a measure of resistance to sudden impact or shock is termed as aggregate impact value which is very significant in the design of highways. Los Angeles test machine is a machine which measures resistance to abrasion of aggregate. For the determination of the abrasion value of road aggregates, we use Deval’s machine. For the determination of the strength of the subgrade soil for design of pavement thickness, California bearing ratio has to be calculated. For any Bituminous material, consistency test has to be carried out by a penetrometer and viscosity by a viscometer. A ring and ball apparatus can be used to determine softening point of Bituminous material.

Heat treatment in metallurgy

In metallurgy, heat treatment is defined as the combination of heating and cooling operations carried out on a metal or alloy in the solid state. Heat treatment helps to achieve desired microstructure and properties. For steel, a wide range of mechanical properties can be accomplished by proper heat treatments. Heat treatment helps to improve mechanical properties such as tensile strength, impact resistance and ductility. It also improves magnetic and electrical properties. By heat treatment we can increase wear resistance, abrasion etc. Heat treatment also helps in improving machinability and refining grains. By suitable heat treatment, we can produce hard surfaces and soft interior portions. There are two types of heat treatment processes. They are full heat treatment and surface heat treatment. Recrystallization annealing, full annealing, partial annealing, process annealing, spheroidising annealing, normalizing, hardening, austempering and mastempering comes in the category of full heat treatment. Surface heat treatment includes pack carburizing, liquid carburizing, gas carburizing, cyaniding, nitriding, carbo-nitriding, flame hardening and induction hardening. Some advanced techniques of heat treatment are ion nitriding, plasma carburizing, electron beam hardening and laser hardening.