Current Affairs Science Projects And Inventions

Most kinds of mechanical movement in appliances are driven by electric motors—fans, fridges, and even computers are all powered in this way. In 1873 Frenchman Theophile-Zenobe Gramme (1826-1901) was the first to show that electricity could be used to move things efficiently. Semiliterate, and with only a grasp of simple arithmetic, he was not a typical inventor. However, his manual skill and logical thinking led to one of the most important applications of electricity. A carpenter by trade, Gramme was appalled by the dirt produced by newly invented electric batteries and decided to concentrate his efforts on improving their design. It had not been long since Michael Faraday in Britain and Joseph Henry in the United States had created dynamos, which converted energy from movement into electricity. These are the devices that convert leg power to light in bicycle lamps and wind power into electricity. Gramme worked hard and greatly improved the original dynamo design. He opened his own dynamo- producing factory and buyers initially used his devices for electroplating and lighting. Motors work in the opposite way to dynamos; they take electrical energy and turn it into something that can make things move. When showing off his improved dynamo design, Gramme connected a dynamo giving out electricity to a reversed device, which then turned the energy back into mechanical energy—demonstrating that it was possible to convert electricity into movement. This was the basis of the DC (direct current) motor. As electricity production became more efficient, the electric motor became an essential component in the development of most household appliances with moving parts—from washing machines to fans and blenders. 

The innocuous spray can has been the subject of some controversial press coverage over the years. Its use as a cheap means of getting "high," termed solvent abuse, involves inhaling the fumes of certain aerosols to achieve an effect a little like being drunk. The aerosol can is also popularly used to spray-paint graffiti and, during the 1970s, the increasing awareness that chlorofluorocarbons were causing damage to the ozone layer led to the use of CFCs being phased out in agreement with the Montreal Protocol. Despite the negative aspects of the product, the aerosol spray can is a ubiquitous invention that enjoys widespread use around the world today. Aerosols date back to the late 1800s, with metal spray cans being tested as early as 1862. The real breakthrough in aerosol technology did not come until 1926 when Norwegian chemical engineer Erik Rotheim (1898-1938) discovered that a payload could be mixed with a propellant in a pressurized canister, allowing the product to be sprayed through a small directional nozzle. The key to the aerosol is in the propellant. The gas used is stored in the can as a pressurized liquid vapor, at a temperature just below its natural boiling point (usually slightly below normal room temperature). When the liquid is released through the nozzle, it evaporates and turns into a gas, thus propelling the product in the form of a spray. Despite its detractors, Rotheim's invention has brought improvements and greater convenience in many areas of activity, from spray paints that produce a satisfyingly even coat on refurbished cars to the improbable but appetizing arabesques of spray- administered whipped cream topping. 

Debate rages over the starting point of the bicycle, butmost experts agree that the nineteenth century was the great era for the development of the bike. British cycle-maker John Kemp Starley (1855-1901) claimed the safety bicycle as his invention, first demonstrating it in 1885. Questions have been raised over Starley's right to this invention as other similar models appeared around the same time, but his version was undoubtedly the best. Starley's Rover Safety model featured spoked wheels of almost equal size, a diamond-type frame, J. H. Lawson's recent invention of the chain-drive (which powered the rear wheel), and an easily adjusted seat and handlebar. The word "safety" was used here for a reason. Previous bicycles were perilous contraptions, especially the penny-farthing (developed by Starley's uncle, James Starley) that immediately preceded the Rover. The penny-farthing's giant front wheel and tiny rear one made it a strange-looking device, with riders perched precariously a long way off the ground. The safety bike was a more sensible height and its design and weight distribution were far better balanced. The new bike featured tangentially spoked wheels—one of James Starley's innovations—but hard rubber tires still made for an uncomfortable ride. When John Dunlop's pneumatic tires were incorporated, however, the safety bicycle became a massive hit. It was also less costly than its predecessors, allowing cycling to become a more widespread activity. Many refinements in the bicycle have since taken place, significantly with the advent of the mountain bike in California during the 1970s. 

The steam shovel, invented in 1839 by William Otis, was used to dig the Suez Canal in 1869 and the Panama Canal in 1910. But eighty years after the invention of a digging machine, trenches were still being filled using mule power. In 1923, American farmer James Cummings (1895- 1981) saw mules being used to backfill oil pipeline trenches and realized that a machine could do the job more efficiently. He and draftsman J. Earl McLeod drew up plans, built the first bulldozer from junkyard parts, and won the contract to backfill the pipeline. The purpose of the bulldozer is to move material from one place to another. Bulldozers have wide tracks to facilitate movement over mud and sand, and a heavy metal plate (or blade) to smooth, push, or carry rocks, sand, soil, or debris. They are the most frequently used earth-moving machines on construction projects today and are essential to quarrying, mining, constructing roads and buildings, and demolition. Bulldozers were critical to the 1944 Allied invasion of Europe. British armored bulldozers cleared beaches and roads and filled in bomb craters. Some tanks were converted into bulldozers by removing the turrets and adding bulldozer blades. Today, armored bulldozers are the mainstay of combat engineers around the world, who use them for constructing earthworks, removing obstacles, clearing mines, and demolishing structures. Bulldozers are also important tools for responding to natural disasters such as earthquakes. A bulldozer can clear a collapsed high-rise building in a few days. Without bulldozers to clear rubble, a city hit by a major earthquake might never recover. 

Sylvan Goldman (1898-1984) was the owner of the Humpty Dumpty supermarket chain in Oklahoma City when in 1937 he struck upon the idea of the shopping cart. Goldman had observed that shoppers would often struggle with the wire and wicker baskets once they became too full, and he realized that this would stop them from buying. His initial inspiration for the design came from a folding chair in his office. Along with employee Fred Young, Goldman designed and built the first shopping cart, which held two wire baskets, one above the other, in a metal frame with wheels at the base. When the carts were not in use, the frame would fold flat, like the chair that suggested the design. Goldman founded the Folding Carrier Basket Co., while a mechanic called Arthur Kosted developed a production line process to mass produce the carts, and began to introduce them in his stores. They were initially unsuccessful as men found them effeminate, and women found them a little too close to strollers. As one customer said to Goldman, "I have been pushing enough baby carriages." Goldman overcame this problem by employing models of both sexes and various ages to use the carts around the store. The carts took off, with a seven year waiting list by 1940, and Goldman made his fortune collecting royalties on every shopping cart until his patents expired. Although his original design did well, Goldman improved it some years later by developing the "nest" carts, now ubiquitous across the world. With a single basket, and significantly more room, this design has to its credit that nothing has been found to replace it after more than seventy years of use. 

"Illegitemi non carborundum. Mock Latin slogan: Don't let the bastards grind you down." Source unknown In 1880 Edward Goodrich Acheson (1856-1931) developed an electrical battery that he tried to sell to the inventor and entrepreneur Thomas Edison. Rather than buying his battery, Edison gave Acheson a job. Despite rapid promotion, Acheson left to become an independent inventor. As the superintendent of a factory that made lamps, he could conduct his own experiments. He wanted to recreate diamonds in the laboratory, but his processes for heating carbon failed. Next he tried mixing day and carbon together by electrically fusing the two. The fused mass he created had dark shiny specks in it, and examining these further he found they were extremely hard. Acheson had created silicon carbide, which he named carborundum, wrongly thinking it to be a compound of carbon and aluminum. In 1893 he received a patent for his discovery. It was the hardest substance made by humankind, second only to diamond, and many realized its potential for the manufacturing industry. Its extremely high abrasiveness made it perfect for making precision- ground machine tools, and Acheson's initial production facility was soon swamped with orders. In the mid-1890s Acheson discovered that by overheating carborundum he could make graphite. Today carborundum is used in sandpaper, disk brakes, ceramic membranes, and bulletproof vests. 

The history of blue jeans can be traced to two men— Levi Strauss (1829-1902), a German who emigrated to the United States as a young boy, and the lesser known Latvian Jacob Davis (1834-1908), who moved to the United States in 1854. In 1853 Levi Strauss moved to San Francisco where he set up a company, Levi Strauss & Co., selling buttons, scissors, bolts of cloth, and canvas. He also designed heavy-duty canvas work overalls for local miners. When his canvas supplies ran out, he began using heavyweight cotton twill, later known as denim. One of Strauss' customers was a tailor, Jacob Davis, who also made work trousers. His clients were complaining that the pockets kept ripping out, so Davis devised a method of strengthening the pocket corners and fly fastenings with metal rivets. This was an immediate success, but Davis did not have the money to obtain the patent, so he approached Strauss. An astute businessman, Strauss paid for the paperwork and the two men filed a joint patent for the new rivet-strengthened work trousers on May 20, 1873. Davis went to work for Levi Strauss & Co., overseeing production of the new work trousers, which were not called jeans until the 1960s. They quickly became popular and their fame as the best work trousers spread throughout the United States. In around 1890 the patent ran out, allowing any company to manufacture riveted jeans. At the same time Levi Strauss & Co. assigned their jeans the number 501. The term Levi's, however, was not coined by the company but by the public, and the company trademarked the name. 

"The launching of the BCG vaccine was ...a gigantic dishonest commercial operation." Dr. Jean Elmiger, Swiss doctor and homeopath Since it was first developed in 1921, the BCG, or Bacille- Calmette-Guerin, vaccine has been given to over a billion people worldwide to prevent tuberculosis. Tuberculosis was a huge killer of adults in the nineteenth century. In 1882 Robert Koch proved that the bacterium tubercle bacillus was the cause. Using it in killed or treated form to protect people from infection did not work, however. French bacteriologist, Albert Calmette (1863-1933) and his colleague, veterinary surgeon Camille Guerin (1872-1961) made a significant step forward when they found that placing bovine tuberculosis in a glycerine-bile-potato mixture caused it to grow bacilli that were less virulent. By 1906, through further subculturing, Calmette and Guerin produced a strain of living bacilli that were so weakened they could not produce disease but could still be used as a vaccine. They first tested their BCG vaccine on humans in 1921, and in 1928 it was used to successfully inoculate 116,000 French children. In -recent years, more cases of tuberculosis are being reported alongside an increase in multi-resistant strains of the bacterium. This has led to trials of a new vaccine to complement the BCG vaccine. The MVA85A, contains a protein found in all strains of tuberculosis that aims to boost the response of T-cells already primed by the BCG vaccine. The new vaccine is being tested in South Africa's Western Cape. 

"When I'm watchin'my TV/ And that man comes on to tell me how white my shirts can be..." The Rolling Stones, "Satisfaction" In 1907 the technology company Henkel launched Persil—the world's first self-acting detergent. This new type of washing powder allowed stubborn stains to be removed from clothes, without the need for rubbing or bleaching. Henkel & Cie was established in Aachen, Germany, in 1876 by Fritz Henkel (1848-1930) and his business partners and the first product they marketed was a universal detergent based on silicate. In 1905, Henkel's youngest son joined the company and began to study the chemistry of washing, bleaching, and peroxide. Persil was one of the first-ever branded products. The name was derived from two of the detergent's ingredients: perborate and silicate. Though Persil proved to be hugely successful commercially, synthetic detergents did not develop until World War I, when problems securing a supply of fats and oils led scientists to seek alternative ingredients. In 1946, a breakthrough launch of "built" detergents gave rise to products that performed better at cleaning heavily soiled garments. Detergents for automatic washing machines were introduced in the 1950s, and the first washing powders to use enzymes were launched in the following decade. The emergence of the dishwasher in the 1980s initiated the birth of a whole new class of detergents. 

"Don't ask me. Ask the metal detector, it's supposed to work...” Manny, from American crime drama series CSI When U.S. President James Garfield was shot in an assassination attempt in 1881 the doctors called on Alexander Graham Bell (1847-1922) to find the bullet in his dying body. For this purpose Bell quickly threw together a makeshift instrument that could detect metal, but unfortunately the President was lying in a bed with a metal frame, unusual at the time, and this interfered with the instrument. Bell eventually realized why his detector was not functioning properly, but it was too late and President Garfield died shortly after. Metal detectors rely on the relationship between electricity and magnetism. A current is run through a coil of wire, and this causes a magnetic field. If a metal object passes through the field, then an electric current will be generated on the object. This, in turn, causes an opposite signal in the coil and this change alerts the user to the presence of metal. Bell's crude metal detector was eventually improved upon, and the modern detector dates from the 1930s. Metal detectors are commonly seen today in airports, where they are used to detect concealed weapons. They are also used to detect land mines on the battlefield and to check food for shards of metal in factories. Simple metal detectors are cheap to buy and easy to make, and some take up metal detecting as a hobby to look for coins and other metal items.