Iron is the main ingredient, but it usually contains carbon too.
steel
nor as well as nand gate are universal gates they both can be used as a complete set of logic gates
Generally for big and major dams,motors are alone not used,all this type dam gates will be controlled manually.Because it is not easy to conrol the large dam gates by motors. But for the dams with single gates,used for irrigation purpose,in canals,we can use the synchronous reversible motors to control such type of dams.
The reason for use of iron making garden gates is that they are resistant to corrosion.
1 gate.
Manhole covers are used for many things. Manhole covers are used to cover up holes in the ground where sewage can be found in order to protect people.
Man-hole covers (inspection covers) are made from heavy, thick cast-iron. Gates can be made from wood or metal.
steel
Round manhole covers are generally used over square manholes because they cannot fall through the manhole openings. There is a chance that if square manhole covers are used they can be turned at an angle and fall through the manhole opening. Round manhole covers can be moved more easily as well.
If they were made of wood they would rot and have to be replaced frequently. The metals used are also inexpensive.
The brittle kind of iron used for making engine blocks and manhole covers is called "ductile iron" or "nodular iron." This material is known for its excellent castability, strength, and wear resistance. Its unique properties make it suitable for heavy-duty applications where durability is essential.
Those metal things in the middle of the road are called "manhole covers" or "manhole lids." They are used to cover openings to underground utility lines and provide access for maintenance and repair work.
A circular manhole cover is used because it cannot fall into the hole it covers regardless of its rotation. This design simplifies installation and removal of the cover, reduces the risk of accidents, and is more cost-effective to manufacture.
A gulley trap will have a water seal and connects each drainage line from the building to the first manhole. One manhole will have one or many drainage line inlets and one outlet that is used to carry drainage water to long distance for disposal.
Bill GATES USED TO BE THE RICHEST MAN IN THE WORLD
"Life is not fair; get used to it." , Bill Gates
light gates are used to brighten up the entrance when it is dark.