Спеціальність: Технологічна освіта
Long ago people noticed that steam has the power of moving things, and they began to wonder how steam could be made to work for them. The first steam-engine was made in ancient Egypt by Hero, a philosopher of Alexandria. It consisted of a hollow globe, which could turn on a pair of pipes and was supplied with steam through one of them. The steam escaped from the globe to the outside air through two bent pipes facing tangentially in opposite directions at the ends of a diameter perpendicular to the axis. The globe revolved by reaction from the escaping steam.
Hero’s engine, called the aeolipile and described in his work “Pneumatica” was regarded merely as a toy. In fact, it was seventeen hundred years before anyone showed any further interest in the idea of a steam-engine. The earliest steam-engine which found employment in industry was that of Thomas Savery in 1698. The engine was used in pumping mines and in raising water to supply houses and towns. A serious difficulty with this engine was that the height which it would lift water was limited by the pressure the boiler could bear.
There were even explosions, as the safety valve had not yet been invented. This was invented by the Frenchman Denis Papin, who was also the inventor of the piston.
The next step forward was taken by the English mechanic Thomas Newcomen, who combined the ideas of Savery and Papin. It was Newcomen who designed an engine that could be used not only to pump water, but also to drive other machinery.
An even better steam- engine was built in Russia in 1765 by the brilliant mechanic Ivan Polzunov. One of the reasons why it was better was that it could be used for many purposes and not just for pumping water. Secondly, Polzunov’s engine had two cylinders. Hence, while the piston in one was going down, the piston in the other was rising. It was therefore the first continuous-action engine.
The next inventor who helped to make the steam-engine what it is today was James Watt, a maker of instruments at the University of Glasgow. The legend is told is that Watt invented the modern steam-engine by watching the steam lift the lid of his boiling tea-kettle. This, of course, is not so. Watt began improving the steam-engine, when one of Newcomen’s engines was brought to his workshop for repairs. This was in 1763. By 1785 he had developed a greatly improved steam-engine, which found many more uses than earlier models had. This led to the Steam Age.
But the story of the steam-engine does not end with Watt. It is progressing with the idea of Hero of Alexandria and his aeolipile which was in fact the first steam-turbine using steam to produce rotary movement.
Dodge Charger LX
The Dodge Charger LX is a rear-wheel drive four-door automobile introduced in February 2005. Built by Chrysler for its North American Dodge brand, the car was created to continue the Dodge Charger line, and replaced the Dodge Intrepid as Dodge's full-size sedan. It shares the LX platform with the Chrysler 300, the newer third-generation Dodge Challenger, and the now-discontinued Dodge Magnum.
The first Charger was a 1964 show car, based on the Dodge Polara and fitted with a 426 Wedge V8 engine. The first production Charger, based on the Dodge Coronet, was introduced as a 1966 model. In 1999, Dodge introduced a new Charger R/T concept car. It took many styling cues from the 1960s Chargers, sharing their long nose and rearward cab, but was much shorter at 187 inches (4,700 mm), compared to 203 inches (5,200 mm) for the 1966 Charger. It was also 650 lb (290 kg) lighter. Although it had four doors where the earlier models had two, the rear doors were intended to be blended unobtrusively into the body.
The Insurance Institute for Highway Safety gives the Charger an overall Good score in frontal crash tests. In side impacts Charger models equipped with optional side airbags are given a Marginal score overall, and models without side airbags are given the lowest overall Poor score.
The National Highway Traffic Safety Administration gives the Charger five stars on passenger, driver, and rear passenger crash test ratings and four stars in regard to side impact rating.
All models come standard with Electronic Stability Program (ESP) (except in 2.7L V6 cars where it is optional) with ABS and all speed traction control.
A new Super Bee version of the Charger debuted at the 2006 New York International Auto Show for the 2007 model year. It shares the SRT-8's 425 hp (317 kW) 6.1 L (370 cu in) Hemi engine but comes in special "Detonator Yellow" paint with black decals. It is a limited edition with only 1000 being produced. A B5 Blue version of the Super Bee was shown at the 2007 North American International Auto Show and went on sale in early 2008, also with a limited run of 1000. 425 Hemi Orange Super Bees were built in 2009.
In early 2006, DaimlerChrysler released a new police version of the Charger. It made its debut at the 2005 New York International Auto Show. Unlike the civilian version, the police version features upgraded heavy-duty brakes, a severe-duty cooling system, police-performance Electronic Stability Program, police performance-tuned steering, and a gear shifter that is mounted on the steering column instead of in the center console. In place of the center console, Dodge has equipped the police edition with an aluminium plate appropriate for mounting radio equipment, computers, and controllers for lights and sirens. The vehicle's electrical system is specifically designed for integration of siren and light controls, and other police vehicle accessories.
A concept vehicle or show vehicle is a car prototype made to showcase a concept, new styling and new technology. They are often shown at motor shows to gauge customer reaction to new and radical designs which may or may not have a chance of being produced.
General Motors designer Harley Earl is generally credited with inventing the concept, or show, car, and did much to popularize it through its travelling Motorama shows of the 1950s.
Concept cars never go into production directly; in modern times all would have to undergo many changes before the design is finalized for the sake of practicality, safety and cost. A "production-intent" vehicle, as opposed to a concept vehicle, serves this purpose.
They are also known as prototype cars, but should not be confused with prototype race cars such as the Le Mans Prototype.
Concept cars are often radical in engine or design. Some use non-traditional, exotic, or expensive materials, ranging from paper to carbon fibre to refined alloys. Others have unique layouts, such as gullwing doors, 3 or 6 (or more) wheels, or special abilities not usually found on cars. Because of these often impractical or unprofitable leanings, many concept cars never get past scale models, or even drawings in computer design. Other more traditional concepts can be developed into fully drivable (operational) vehicles with a working drive train and accessories. The state of most concept cars lies somewhere in between and does not represent the final product. A very small proportion of concept cars are functional to any useful extent, some cannot move safely at anything above 10 mph.
Inoperative "mock-ups" are usually made of wax, clay, metal, fiberglass, plastic or a combination thereof.
If drivable, the drive train is often borrowed from a production vehicle from the same company, or may have defects and imperfections in design. They can also be quite refined, such as General Motors' Cadillac Sixteen concept.
After a concept car's useful life is over, the cars are usually destroyed. Some survive, however, either in a company's museum or hidden away in storage. One unused but operational concept car that languished for years in the North Hollywood, California shop of car customizer George Barris, Ford Motor Company's "Lincoln Futura" from 1954, received a new lease on life as the Batmobile in the Batman series that debuted in 1966 on the ABC Television Network.
The Ford Nucleon was a scale model concept car developed by Ford Motor Company in 1958 as a design on how a nuclear-powered car might look like. The design did not include an internal-combustion engine, rather, the vehicle was to be powered by a small nuclear reactor in the rear of the vehicle, based on the assumption that this would one day be possible based on shrinking sizes. The car was to use a steam engine powered by uranium fission similar to how nuclear submarines work.
It is fair to start talking about automobile wheels starting with Karl Benz's 1885 Benz Patent Motorwagen. The three-wheel vehicle used bicycle-like wire wheels, which were fitted with hard rubber.
Speaking of rubber, the first people who thought about using it for automobile purposes were André and Edouard Michelin, who later founded the famous tire company. In 1910, the B.F. Goodrich Company invented longer life tires by adding carbon to the rubber.
Overseas, Ford's Model T used wooden artillery wheels, which were followed in 1926 and 1927 by steel welded-spoke wheels. Unlike Karl Benz's first vehicle, the car that "put America on wheels" had pneumatic tires invented by Mr. Dunlop. There was, however, a big difference between those tires and the ones we used today. Made of white carbonless rubber, the tire had a life expectancy of around 2000 miles. A tire only lasted for around 30 or 40 miles before it needed repairs. Common problems included: the tire coming off the wheel, punctures and the tube being pinched.
Paradoxically, the next step in wheel evolution was the disc one, which bears more resemblance to the initial solid designs. As with many other things in our history, the change was prompted by lower costs as the steel disc wheels were cheaper to make. The rim could be rolled out of a straight strip of metal, and the disc itself could be stamped from sheet metal in one easy motion. The two components were welded or riveted together, and the resulting wheel was one that was relatively light, stiff, resistant to damage, easily produced in mass quantities, and most important, cheaply produced.
Today there are basically two types of wheels for automotive use, steel and alloy, both of which have benefited from the technological advancements. As a result, the massive, heavy wheels of the early automobile days have become lightweight, strong spoked units. It's worth noting that just as the first solid wheels turned to the spoked design in the relatively early stages of humanity, so did in the 20th century.
Though we won't get too technical about the differences between steel and alloy wheels, we will say that the latter are lighter and better heat conductors. As a result, cars fitted with alloy wheels sport improved steering and handling and prolong the life of the brakes. They are also more visually appealing, but that's another story. On the other hand, alloy wheels are considerably more expensive to make than steel ones, which raises the overall price of the car.
As the traditional wheel design is close to exhausting any possible development, companies are looking at more and more exotic prototypes to replace it. Among these, Michelin is probably the most active in the field of research with two recent innovative concepts, the Tweel and the Active Wheel System.
Agricultural machinery is machinery used in the operation of an agricultural area or farm.
With the coming of the Industrial Revolution and the development of more complicated machines, farming methods took a great leap forward. Instead of harvesting cereal and grain by hand with a sharp blade, wheeled machines cut a continuous swath. Instead of threshing the grain by beating it with sticks, threshing machines separated the seeds from the heads and stalks.
Power for agricultural machinery was originally supplied by horses or other domesticated animals. With the invention of steam power came the portable engine, and later the traction engine, a multipurpose, mobile energy source that was the ground-crawling cousin to the steam locomotive. Agricultural steam engines took over the heavy pulling work of horses, and were also equipped with a pulley that could power stationary machines via the use of a long belt. The steam-powered machines were low-powered by today's standards but, because of their size and their low gear ratios, they could provide a large drawbar pull.
The internal combustion engine became the main source of power for the next generation of tractors. These engines also contributed to the development of the self-propelled, combined harvester and thresher, or combine harvester (also shortened to 'combine'). Instead of cutting the grain stalks and transporting them to a stationary threshing machine, these combines cut, threshed, and separated the grain while moving continuously through the field.
Combines might have taken the harvesting job away from tractors, but tractors still do the majority of work on a modern farm. They are used to pull implements—machines that till the ground, plant seed, and perform other tasks.
Tillage implements prepare the soil for planting by loosening the soil and killing weeds or competing plants. The best-known is the plow, the ancient implement that was upgraded in 1838 by John Deere. Plows are now used less frequently in the U.S. than formerly, with offset disks used instead to turn over the soil, and chisels used to gain the depth needed to retain moisture.
The most common type of seeder is called a planter, and spaces seeds out equally in long rows, which are usually two to three feet apart. Some crops are planted by drills, which put out much more seed in rows less than a foot apart, blanketing the field with crops. After planting, other implements can be used to cultivate weeds from between rows, or to spread fertilizer and pesticides. Hay balers can be used to tightly package grass or alfalfa into a storable form for the winter months.
Modern irrigation relies on machinery. Engines, pumps and other specialized gear provide water quickly and in high volumes to large areas of land. Similar types of equipment can be used to deliver fertilizers and pesticides.
Besides the tractor, other vehicles have been adapted for use in farming, including trucks, airplanes, and helicopters, such as for transporting crops and making equipment mobile, to aerial spraying and livestock herd management.