Urban spheres of influence and rural urban fringe

Urban spheres of influence and rural urban fringe Urban spheres of influence Urban spheres of influence reflect centre-to-hinterland relationship, compared with the non-central region, the centre assumes more complex economic functions, and provides more economic activities. Famous theoretical contributions to this research field are the Central Place Theory (Christaller, 1933), the extension to the Central … Read more

Metallurgy concentration, roasting, smelting

Metallurgy concentration, roasting, smelting Roasting It is a process wherein the ore is heated either alone or with some other material in excess of air below the fusion point of the ore. Usually, this method is used for sulphide ores. In roasting, definite chemical changes take place to form oxide or chloride of the metal. … Read more

Preparation of nitrogen

  Preparation of nitrogen Nitrogen is found in both free and combined states. It occupies 78.07% by volume. Nitrogen can be prepared: By heating copper in air: Firstly, air is passed through lime water and then concentrated sulphuric acid to make the air free from carbon dioxide and moistures respectively. The air contains only nitrogen … Read more

The Rate of a Chemical Reaction

The Rate of a Chemical Reaction The rate of a chemical reaction can be defined as the amount of the reaction which occurs in unit time. The rate of a reaction is measured by choosing certain properties of the reaction which will indicate how far the reaction has gone, and whose magnitude can be observed … Read more

Quality of life, life expectancy, literacy, standard of living and migration in India

Quality of life, life expectancy, literacy, standard of living and migration in India Human development—a comprehensive approach Human development is a process of enlarging people’s choices. But human development is also the objective, so it is both a process and an outcome. Human development implies that people must influence the processes that shape their lives. … Read more

Properties of soaps and detergents

Properties of soaps and detergents Soap – Characteristics And Uses Soaps are excellent cleansing agents and have good biodegradability. A serious drawback which reduces their general use, is the tendency for the carboxylate ion to react with Ca+ and Mg+ ions in hard water. The result is a water insoluble salt which can be deposited on … Read more

Refining of ores Metallurgy

 Refining of ores Metallurgy Metallurgy Metallurgy is the process of obtaining metals from ores. It may be defined as the processes which are involved in the extraction of metals from their ores and then refining them for use are known as metallurgy. Steps of Metallurgy: Metals can be extracted from their ores by following processes: Enrichment of … Read more