+ Bicycle By Ragad and Hiba

+ The History of Bicycle: In 1816 the German Baron Karl von Drais devised a steerable hobby horse, and within a few years, hobby-horse riding was a fashionable pastime in Europe. Riders also discovered that they could ride the device with their feet off the ground without losing their balance. And so, in 1840, a Scottish black-smith named Kirkpatrick Macmillan made a two-wheel device that was operated by a treadle. A couple decades later, a Frenchman, Ernest Michaux, designed a hobby horse that utilized cranks and rotating pedals connected to the front axle.

+ Old and new bicycle: 1.It should be fast, have all the size for all the ages, easy to transforming, and something doesn’t rust light. 2. The bicycle change because they want the rider more comfortable. 3. The heavy materials make the movement hard, but now the light materials make the movement more easier then the old bicycle.

+ What Materials used in Bicycle?? The old bicycle made of: Steel. Aluminum The new bicycle made of: Steel Aluminum Titanium Carbon fiber

+ Steel: The chemical formula of the steel is Fe 3 C. Steel is covalent because it transferred between non-metals to non-metals. The properties of steel vary widely, depending on its alloying elements. The production of steel benefits the World in great ways. First, the standard of living goes higher as there exist new jobs in banking, iron ore and manganese mining, office jobs, transport jobs. The steel recycle. If we only recycle one-tenth of the cans we now throw away, we'd save about 3.2 billion of them every year.

+ When and where the steel discovered: steel was discovered in 1913 by Sheffield metallurgist Harry Brearley.

+ Advantage and Disadvantages: Advantage: Steel has the highest strength to weight ratio of any building material. No twisting or warping. Fire parapets can be eliminated. Slower aging process with less maintenance. Easily disassembled for repairs Disadvantages: Heavy and thus expensive to transport. Steel is an excellent thermal conductor requiring additional exterior insulation or thermal breaks to overcome this disadvantage Steel components can rust if left exposed in marine climates. Finding steel roof trusses is difficult in most areas

+ Aluminum: The chemical formula of aluminum is A1 3, aluminum is non-metals. Aluminum is a metallic element, and its structure is very similar to most other metal. Aluminum is made up of crystals It is not soluble in water under. Aluminum is the most abundant metal in the Earth's crust. Recycling aluminum cans is easy. When they are empty, rinse them out so they are clean and either return them to the store for deposit or recycle

+ When and where the Aluminum discovered: In England in the early 1800s, Humphry Davy was the first one who discovered the steel.

+ Advantage and Disadvantages: Advantage: Won't swell, chip or rust. Does not deteriorate. Reduced weight. increased strength & durability. Covers can be retrofitted for existing structures. Low Surface Hardness Disadvantage: Aluminum is more expensive than steel Aluminum can corrode quickly if suitable precautions against electrolysis are not taken. Aluminum can be water- stained easily.

+ Titanium: Titanium is chemical element with the symbol Ti and atomic number 22. Titanium is metal. Transition metal with a silver color. White metal when pure. Titanium is as strong as some steels. Titanium is transition metal. The metal has a low density.

+ When and where the Titanium discovered: Titanium was discovered in 1791 by William Gregor in Cornwall, during his study of magnetic sand.

+ Advantage and Disadvantages: Advantage: It is corrosive resistant. It can withstand high temperatures. Light but Strong. has excellent corrosion resistance. Disadvantages: Expensive metal. Processes for forming and joining titanium are complex and expensive. Expensive to cast.

+ Carbon fiber: There is no single formula for a carbon fiber. Carbon fiber is non-metal. Carbon fiber is crystalline material. White metal when pure. High chemical resistivity. Rigid materials that are resistant to stretching and compression. a black, lustrous solid

+ When and where the Carbon fiber discovered: Carbon fibers were discovered in the late 1800s when Thomas Edison was testing materials to use as a filament in the first incandescent bulb.

+ Advantage : It can be formed to most any shape. it's non-corroding. High wear resistivity and moisture absorbance. High thermal resistivity under non oxygen atmosphere. High modules {200~650Gpa} and high rigidity.

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+ We hope you like it. By Hiba and Ragad