If the percentage of sulphur is less than 0.5% in petroleum, then it is called sweet crude oil. It came to be called ‘sweet’ because the low level of sulphur gives the oil a mildly sweet taste and pleasant smell. It also contains a small amount of hydrogen sulphide and carbon dioxide.

The Mute Swan has been a domesticated bird in England for over 800 years. It is sometimes called the ‘royal’ bird and in fact by the thirteenth century all the swans in England belonged to the Crown. People were allowed to keep swans on open water as long as the birds were prevented from flying away, and they carried their …

Surface diffusion is a general process involving the motion of adatoms (adsorbed atom lying on a crystal surface, used in surface chemistry, when describing single atoms lying on surfaces and surface roughness), molecules, and atomic clusters (adparticles) at solid material surfaces. Tunnelling diffusion is a particularly interesting example of an unconventional mechanism wherein hydrogen has been shown to diffuse on …

Ploughing one month in advance i.e. in the month of May for kharif crops is known as summer ploughing. There are the three usual harvests known as the kharif or autumn (June-September), the rabi or spring (October-March) and zaid or extra harvest (March-June). Summer ploughing helps to kill weeds, hibernating insects and diseasecausing organisms by exposing them to the summer …

This is a disorder of speech in which some sounds are difficult to produce. It may bear some relationship to tensions experienced by a growing child. Treatment is usually through psychotherapy or speech therapy to which it responds well, and the earlier the better.

In the 17th century, Sir Isaac Newton discovered the universal gravitational force. In the 21st century, Navinchandra K Shah, Prof. P N Jain and Prof. P P Jain of Hubli discovered a universal repulsion force (URF). It’s an astronomical force exerted by the sun and stars and therefore called stellar repulsion force (SRF). The science which deals with repulsive phenomena …

Stevenson’s Screen is a wooden box fitted into a steel frame, specially designed to protect weather instruments like thermometer, barometer, etc. from the sun’s rays and other natural heat radiation. British civil engineer Thomas Stevenson designed the first Stevenson’s Screen in 1818. In order to prevent direct sunlight falling on the instruments, it was designed so the door opens to …

Spider silk, also known as gossamer, is a protein fiber spun by spiders. Spiders use their silk to make webs. They can also suspend themselves using it. Many small spiders use silk threads for ballooning, the scientific term for the dynamic kiting spider lings (mostly) used for dispersal. They extrude several threads into the air and let themselves get carried …

Soap is made largely from fats or oil, with a variety of other ingredients. Before the introduction of soap in the 1st Century A.D. people ‘washed’ themselves and their clothes with fuller’s earth, a fine clay-like substance that loosens oil and dirt. People first made their own soap by saving scraps of fat and boiling them in an iron pot. …

This is a new and promising technology in the field of wireless and mobile communications in which capacity and performance are usually limited by two major impairments — multipath and co-channel interference. Multipath is a condition that arises when a transmitted signal undergoes reflection from various obstacles in the environment. This gives rise to multiple signals arriving from different directions …