Facebook is an American online social media and social networking service owned by Facebook, Inc. In 2004, Mark Zuckerberg launched the Facebook for the first time with Harvard College students and roommates. And also it’s name comes from the face book directories often given to American university students. Membership was initially limited to Harvard students but […]
A turbine is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator. In a turbine, moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Windmills and waterwheels are […]
වැසූ ශාලාවෙන් හඬක් පිටවීමට නොහැකි නිසා ඒවා බිත්තිවල වැදී ආපසු පරාවර්තනය වේ. එම හඬ නැවත නැවතත් පරාවර්තනය වේ. එකම හඬ හඬවල් කිහිපයක් සේ ඇසෙන්නේ එම නිසායි.
කටුස්සා පාට වෙනස් කරන්නේ තම ජීවිතය ආරක්ෂා කර ගැනීම පිණිසය. කොළ අත්තක වැසූ විට ඔහු කොළ පාටය. ගසක කඳක සිටින විට ඌ දුඹුරු පැහැයෙන් යුක්තයි. නො එසේ නම් කොළ. කහ හෝ කොළ, රතු හෝ කහ කොළ වැනි වර්ග දෙකකින් සමන්විතයි. මෙම වර්ණ වර්ධක සෛල කටුස්සාගේ සමේ සෛලවල පිහිටා ඇත. ඌට අවශ්ය වූ විට එනම් බියපත් […]
Transistors are one of the basic building blocks of modern electronics. The first working transistor was a point-contact transistor. It was invented in 1947 by American physicists John Bardeen and Walter Brattain while working under William Shockley at Bell Labs in New Jersey. As a result Shockley, Bardeen and Brattain were jointly awarded the 1956 […]
ඉන්සියුලින් හෝමෝනය ප්රෝටීනයකි. ඒවා ආමාශ ගතවූ විට පෙප්සීන් සැදී රුධිරයට එකතුවීමට ඇති ඉඩකඩ අඩු නිසා ඉන්සියුලින් කෙලින්ම සිරුරට එන්නත් කරනු ලබයි. ඒවා ඉක්මනින් ලේ වලට මුසුවී සිරුරට අවශෝෂණය වේ. මෙමඟින් දියවැඩියාව ඇති පුද්ගලයින්ගේ රුධිරයේ සීනි මට්ටම පාලනය කිරීම සිදු වේ.
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The first commercially successful engine that could transmit continuous power to a machine was developed in 1712 by Thomas Newcomen. There, he improved the steam water pump developed in 1698 by Thomas Savery. However Thomas Newcomen was the inventor of the first successful steam engine.
Cars came into global use during the 20th century. But the year 1886 is regarded as the birth year of the modern car when German inventor Karl Benz invented the first true automobile. It is known as “Motorwagen”. However in the present we have electric cars, hybrid cars and so on.
A battery is a power source consisting of one or more electrochemical cells with external connections. They are used for powering electrical devices such as flashlights, mobile phones, and electric cars. Italian physicist Alessandro Volta is generally credited with discovering the first practical battery. He invented his battery in 1800, it consisted of discs of […]
A printing press is a mechanical device for applying pressure to an inked surface resting upon a print medium (such as paper or cloth), thereby transferring the ink. In Germany, around 1440, goldsmith Johannes Gutenberg invented the printing press, which started the Printing Revolution. However with development of the technology we can find printers with developed features.
