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 Context  Air pollution  Sources of air pollution  Short term effects of air pollution  Long term effects of air pollution  What is Air pollution?   Air pollution is generally accomplished through the pollutants of gases and solid and liquids particles of both organic and inoragnic chemical. Air pollution  is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. Sources of Air pollution   Indoor Air Pollution Pollution enters the Earth's  atmosphere  in many different ways. Most  air pollution  is created by people, taking the form of  emissions  from factories, cars, planes, or  aerosol cans . Second-hand  cigarette   smoke  is also  considered   air pollution . These  man-made  sources of pollution are called  anthropogenic sources ...

Soil mechanics part 1,  types of soil Formation of soils,  Classification of soils, Types of soils,  ,    Soil   The term soil has various meaning, depending upon the genral professional field in which it is being considered. To an agriculturist, soil is the substance existing on the Earth's surface, which grows and develop plant life. To the geologist also , soil is the material in the relatively thin surface zone within which roots occur, and all the rest of the crust is grouped under the term rock irrespective of its hardness. Formation of soil   Soils are formed by the disintegration and decomposition of rocks. The disintegration of rocks is caused by . Mechanical weathering .  Chemical decomposition. Biological decomposition. Mechanical weathering . It is also known as physical weathering.It can be as follows. (i)- Plant roots.. Plants and tress grow in rocks.The roots of these tree and plants enter into the cracks and fissures of the rocks ....

  विशेष प्रकार की कंक्रीट  (1) - उच्च भार वाली  कंक्रीट (२) - कम भार वाली कंक्रीट (३) -  उच्च  सामर्थ्य कंक्रीट (४) - पूर्व-पैक कंक्रीट (५) - पॉलिमर कंक्रीट  (६) - रेशा  प्रबलित कंक्रीट (७) - रेडी मिक्स कंक्रीट (RMC) (८) -प्रबलित सीमेंट कंक्रीट    (1) उच्च भार वाली कंक्रीट ऐसी कंक्रीट जिसका यूनिट भार 30 किलो न्यूटन / घन मीटर से 64 किलो न्यूटन/ घन मीटर होता है ,ऐसी कंक्रीट को उच्च भार वाली कंक्रीट कहते हैं ।इस प्रकार की कंक्रीट के लिए उच्च विशिष्ट गुरूत्व वाला मोटा मिलावा इस्तेमाल किया जाता है।इस कंक्रीट मे मोटे मिलावे के रूप में मैग्नेटाइट ,हेमेटाइट को उपयुक्त माप में तोड़कर प्रयोग किया जाता है। उच्च भार वाली कंक्रीट गमा किरणों को काफ़ी हद तक अवशोषित कर लेती है,इसी कारण इसका प्रयोग नाभिकीय रियक्टर मे किया जाता है.  (२) - कम भार वाली कंक्रीट सामान्य कंक्रीट (24 kN / m3) की तुलना में हल्के वजन वाले कंक्रीट का वजन हल्का होता है (1.6 kN / m3 से 22 kN / m3)। इस कंक्रीट का इकाई भार ,सामान्य कंक्रीट से काफी कम होता है कम भार वाली कंक्रीट उपरी फ...

  Definition of environment  Environment consists of all sum total of the stimulation that the individual receives from conception until death . It covers all those circumstances which assert their influence receives from conception untill death.  Ecology ecology is a new science which deals with the various principles which govern the relationship and interdependence between organisms and their environment.  Characteristics of ecology 1- It is science study for analysis the relation between organism and environment.  2 it include the structure and function together for full understanding of this vast Nature. 3 it is the study of interrelationships and interdependence between organisms and environment.  4 it is the study of organisms in relation of their environment  5 it is the science of all the relations of all organisms to all their environments  6 it is the science of ecosystem . The ecosystem is an important ecological unit  7 it is...

 Context  Merits and Demerits of concrete. Strength of concrete  Durability of concrete  Workability of concrete  Consistency of concrete  Merits  of concrete   1- Ingredients : ingredients of concrete are found everywhere and are cheap. 2 Simple production : the production of concrete is very simple compare to other building materials such as brick and steel  3 Desire casting : it can be molded into any shape and size in the wet state . It can be delivered to any place by pumping.  4-Desired Properties : Concrete is an artificial building material. In this the desired properties can be developed as required.  5-Strength comparession strength of concrete is more than brick masonry and wood  6- Safe concrete is much less affected by sun , rain dampness , fire , water etc  7-Anti pest - it is safe from termites and pests  8- Age It is a durable substance, its age is very much 60-100 years  9- Maintenance  ...

  Concrete   It is obtained by mixing cementing material,water ,and aggregate,and sometimes admixture in required proportions. Concrete = cementing material + aggregates+ water ,  Advantages of concrete   1)- concrete is economical in the long run as compared to other engineering materials 2)- concrete possesses high compressive strength ,and the corrosive and weathering effects are minimum. When properly prepared its strength is equal to that of a hard natural state. 3)-The formwork can be reused a number of times for similar jobs resulting in economy. 4)- concrete can be pumped and hence it can be laid in sufficient position . 5)- concrete is durable ,fire resistant and require very little maintenance. Disadvantages of concrete 1)- concrete has low tensile strength and hence cracks easily. 2)- fresh concrete shrinks on drying and hardened concrete expands on wetting. 3)- concrete under sustained loading undergoes creep, resulting in the reduction of prestress...