bicycle by ragad and hiba
DESCRIPTION
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.TRANSCRIPT
Bicycle By Ragad and Hiba The History of Bicycle:
In 1816 the German Baron Karl von Drais devised a steerable
hobbyhorse, and within a few years, hobby-horse riding was a
fashionablepastime in Europe. Riders also discovered that they
could ride thedevice with their feet off the ground without losing
their balance. Andso, in 1840, a Scottish black-smith named
Kirkpatrick Macmillan madea two-wheel device that was operated by a
treadle. A couple decadeslater, a Frenchman, Ernest Michaux,
designed a hobby horse thatutilized cranks and rotating pedals
connected to the front axle. What Materials used in Bicycle??
The old bicycle made of: Titanium aluminum carbon fiber The new
bicycle made of: Steel Aluminum Titanium Carbon fiber Steel: The
chemical formula of the steel is Fe3C.
The properties of steel vary widely,depending on its alloying
elements. The production of steel benefits theWorld in great ways.
First, thestandard of living goes higher asthere exist new jobs in
banking, ironore and manganese mining, officejobs, transport jobs.
The steel recycle. If we only recycleone-tenth of the cans we now
throwaway, we'd save about 3.2 billion ofthem every year. Advantage
and Disadvantages:
Steel has the highest strengthto weight ratio of any
buildingmaterial. No twisting or warping. Fire parapets can
beeliminated. Slower aging process with lessmaintenance. Easily
disassembled forrepairs Disadvantages: Heavy and thus expensive
totransport. Steel is an excellent thermalconductor requiring
additionalexterior insulation or thermalbreaks to overcome
thisdisadvantage Steel components can rust if leftexposed in marine
climates. Finding steel roof trusses isdifficult in most areas
Aluminum: The chemical formula of aluminum is A13.
Aluminum is a metallic element, and itsstructure is very similar to
most othermetal. Aluminum is made up of crystals It is not soluble
in water under. Aluminum is the most abundant metalin the Earth's
crust. Recycling aluminum cans is easy.When they are empty, rinse
them out sothey are clean and either return them tothe store for
deposit or recycle Advantage and Disadvantages:
Won't swell, chip or rust. Does not deteriorate. Reduced weight.
increased strength &durability. Covers can be retrofitted
forexisting structures. Low Surface Hardness Disadvantage: Aluminum
is more expensivethan steel Aluminum can corrode quicklyif suitable
precautions againstelectrolysis are not taken. Aluminum can be
water- stained easily. Titanium: Titanium is chemical elementwith
the symbol Ti and atomicnumber 22. Transition metal with a
silvercolor. White metal when pure. Titanium is as strong as
somesteels. Titanium is transition metal. The metal has a low
density. Advantage and Disadvantages:
It is corrosive resistant. It can withstand hightemperatures. Light
but Strong. has excellent corrosionresistance. Disadvantages:
Expensive metal. Processes for forming andjoining titanium are
complexand expensive. Expensive to cast. Carbon fiber There is no
single formula for a carbon fiber. is a
Carbon fiber is crystallinematerial. White metal when pure. High
chemical resistivity. Rigid materials that areresistant to
stretching andcompression. a black, lustrous solid Advantage :
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.
sam.davyson.com/.../aluminium/.../structure.html We hope you like
it. By Hiba and Ragad