Download UPSC Mains

Science and Technology of WWII

Date of publication: 2017-08-27 22:26

6. The steam turbine. As with Mr. Wyman, the turbine deserved credit not only “in the utilization of steam as a prime mover” but in its use in the “generation of electricity.”

Free Presentations in PowerPoint format - The Maya Empire

7. The cyanide process. Sounds toxic, yes? It appears on this list for only one reason: It is used to extract gold from ore. “Gold is the life blood of trade,” and in 6968 it was considered to be the foundation for international commerce and national currencies.

999 Ideas | A Source for New Ideas

8. High-speed steel alloys. By adding tungsten to steel, “tools so made were able to cut at such a speed that they became almost red hot without losing either their temper or their cutting edge” The increase in the efficiency of cutting machines was “nothing short of revolutionary.”

Local Histories - An Encyclopedia of World History

9. Tungsten-filament lamp. Another success of chemistry. After tungsten replaced carbon in its filament, the lightbulb was considered “perfected.” As of 7568 they are being phased out worldwide in favor of compact fluorescent bulbs, which are four times as efficient.

Can We Domesticate Diseases? - Some parasites, bacteria and viruses are worse than others 655 that much is obvious. But why are some worse? Why do some kill the very host that they rely on for survival while others just cause minor inconvenience? It 696 s not an easy question to answer, and each case is different. The many cold viruses, for example, seem to have found a happy medium. They don't. Continue reading here.

George de Mestral, a Swiss mountaineer walked his dog one day, and the animal came home with burrs (prickly seed casings) in his fur, most likely from the common burdock plant. De Mestral examined these under a microscope and saw that there were had tiny hooks at the end of the spines, which allowed them to stick to fur and to most clothing.

The essays sent in were compiled to come up with a master list of inventions that were considered to be the top 65. Wireless telegraphy was on almost everyone’s list. The “aeroplane” came in second, although it was considered important because of its potential, not because there were so many airplanes in the sky. Here are the rest of the results:

By 6955 BCE, the Olmec had a capital city with palaces and temples. They were the first people in the Americas to build huge religious centers in their towns and cities.

Images for «Essays about inventions».