Archives June 2013

The annual school sports day is celebrated in our school with great preparations. This day gives us a great pleasure. We are full of joy on that day The 15th December was our sports day this year As usual an interesting programme was made for the day we got printed copies of the programme. The Principal invited parents also. The Senior P.T.I, was in charge of the whole show. The sports began exactly at 10 A.M.  First of all, the athlete taking part in different events, staged a march past. The Principal of the school took the salute. Then the sports began. The first item was that of the races- of 100 metres race the 400 metres race and 880 metres race and five kilometres race the five kilo metres race was a great fun. The hurdle race was also enjoyable. It was a great fun to see the boys more...

Tea was grown for the first time in China. Tea is the most popular beverage in the world today. It is liked by the poor and the rich alike. Tea is a plantation crop. Now it is grown in large quantities in different hilly areas of India and Sri Lanka. In India, Assam, West Bengal, Tamil Nadu and Kerala are the major tea-producing states. Darjeeling tea is famous for its fine flavour. A tea plant is an evergreen bush, three to ten metres in height. It is regularly pruned to keep its height within one to two metres. For its cultivation, regular heavy rainfall, hot and humid weather and sloping land is necessary. Only a few buds and tender leaves are plucked from each tea plant. Then they are rolled and roasted, curled and crushed in the factory. Thus, tea is made ready for the market. We buy it from more...

As soon as hypertext was unveiled to the public in 1968 at the Convention Center of San Francisco in the United States, technology experts knew it was unique. The demonstration, now known as the "Mother of All Demos," showed how this tool for data organization enabled the user to read information, not just in the linear way we read regular text, but for the first time in a dynamic and interactive way. Hypertext later became the fundamental-language of the Internet in Hyper Text Markup Language (HTML), and has revolutionized the way information is accessed. Whereas standard text is read linearly (for instance, Western scripts are read left to right, top to bottom), hypertext allowed the user to retrieve information by “clicking" on link's that shifted the page, opened further texts, and activated video and audio. The forerunner of this breakthrough was called the Memex system (from MEMory Extender), imagined by more...

"Regenerative braking improves overall efficiency and prolongs brake component life." Industrial equipment advertisement Regenerative brakes were designed by the American Motors Corporation (AMC) in the 1960s as a way to increase the potential range of electric cars and match the performance of their fossil fuel-burning contemporaries. The resulting car, the Amitron, built in 1967, never made it into full production. A brake is a device that converts kinetic energy (movement) into another type of energy. Traditional braking systems use the friction of a brake pad to slow down the vehicle, turning its kinetic energy into heat. This system is effective but not energy-efficient—it would be much more resourceful to try to recover some of the kinetic energy back in the form of fuel. The problem with vehicles powered by the internal combustion engine and fossil fuels is that it is impossible to turn inertia back into petroleum. In an electric more...

"The impact of Chinese firearms in terms of war fare and territorial expansion was profound." Sun Laichen, Asia Research Institute A musket is a smoothbore firearm loaded from the muzzle and fired from shoulder-level. It is larger than an arquebus and often fired from a rest on which it can be pivoted from side to side. It is difficult to pin down with certainty when the musket was invented, although according to ancient Chinese texts it was some time in the fourteenth century. Basic cannons had been fashioned by the Chinese, and Chinese weapons experts were the first to produce a device that was recognizable as a musket, but it was when this technology met the greater metallurgical prowess of the Ottoman Empire (and later that of the European powers) that a revolution in warfare took place. It took a long time for muskets to become established; early muskets in more...

When British electrical engineer John Ambrose Fleming (1849-1945) invented the first thermionic diode, he had no idea of the impact it would have on the technology of the twentieth century. The diode is used in many electrical and electronic systems. In its early valve form, the diode used thermionic emission—the flow of electrons within a sealed vacuum—to create a one-way valve for electrical current. This is critical in regulating voltages, processing high-frequency signals, and in converting AC (alternating current) to DC (direct current). Predictably, Thomas Edison, was one of the first to discover the underlying principles. In 1883 he created a kind of diode by modifying an electric light bulb. He patented what he called his "Edison Effect," but ultimately saw little potential in its development. In 1904, having acquired a number of Edison Effect bulbs from the United States, Fleming developed an "oscillation valve," which he used to convert more...

Installing at least one smoke detector in your house Is estimated to halve the chances of a fatal fire, which means that thousands of lives have been saved worldwide since home devices were introduced in the late 1960s. The forerunner of the modern detector was invented by the British electrical engineer George Darby in 1902. His device, which detected heat rather than smoke, consisted of two electrical plates with a wedge of butter between them. As the room temperature rose, the butter melted, causing the two plates to fall onto each other triggering the alarm, and presumably dripping butter everywhere. The most common smoke detectors now use an ionization chamber, a device developed by the Swiss physicist Ernst Meili in 1939 to detect poisonous gases in mines, although not specifically smoke. In the ionization chamber, a radioactive material produces ions (electrically charged atoms). In the presence of smoke, the flow more...

A pyrometer is a device for measuring high temperatures, specifically those above 673°F (356°C), the boiling point of mercury. John Frederic Daniell (1790-1845), the first professor of chemistry at King's College, London, invented an instrument known as a register pyrometer in 1830. This used the expansion of platinum to indicate, for example, the temperature of liquid silver. The platinum bar was placed in a hollow cylinder of plumbago, and the expansion was registered using a lever system and scale. Daniell also went on to invent an electrical battery that became known as the Daniell cell, and a dew-point hygrometer. As the nineteenth century progressed, the accurate measurement of temperature became ever more Important in manufacturing processes involving such things as pottery kilns and steel furnaces. Devices were also required that would measure temperatures up to around 5,400°F (3,000°C). Since these devices had to be distant from the high-temperature object, the more...

Subhash Chandra Bose was one of the greatest leaders of India. He is famous by the name of Netaji. He gave up his life for his motherland. His death is a great loss to the country. Subhash Chandra Bose was born on 23rd January 1897 in Cuttack. His father was a famous lawyer. He came of a very well- to-do family. Even as a child he showed signs of future greatness. He was a very brilliant boy at school. When a European professor made some bad remarks for Indians in the school he beat him. He was expelled from the school. He passed the Matriculation Examination from Cuttack. Then he joined the Presidency College, Calcutta. He passed his B.A. from another college in the first division. Then he went to England and took the Tripose degree from Cambridge University. He also passed the I.C.S. Examination. But he was not interested more...

"Did you ever observe to whom the accidents happen? Chance favors only the prepared mind." Louis Pasteur, French chemist and microbiologist At the beginning of the 1860s French chemist Louis Pasteur (1822-1895) observed that living cells, known commonly as yeast, were responsible for forming alcohol from sugar and, when contaminated, led to its souring. He was able to distinguish and separate these microorganisms, and, in 1862, he and French physiologist Claude Bernard (1813-1878) showed that most of the bacteria present in milk could be killed if the milk was heated to 145°F (63°C) for thirty minutes. The milk was then rapidly cooled to eliminate bacterial contamination. Pasteur applied the same principle to beer, the souring of which was a sore point in the French economy. This process of extended heating came to be known as "pasteurization." Pasteur's revolutionary understanding of germ theory finally brought to an end the centuries-old notion more...