Mechanical Engineering

by using a non-compressible fluid, it acts like a solid push-rod.

You divide the actual output by the potential output and multiply it by a hundred for a percentage. For example, if a plane carries 40 people, and it has 50 seats, 40 people would be actual, but the plane has potential to carry 50, so you do 40 divided by 50 multiplied by 100 for a percentage. 40 divided by 50 = 0.8 0.8 x 100 = 80 80%

Mild steel (grade A36) has a minimum yield of 36,000 psi. A572 grade 50 has a minimum yield of 50,000 psi.

June 11, 1829, by Deming Jarves, the founder of the Boston and Sandwich Glass Company. His knobs had an integral glass screw shank

It is a D.T. item used for clamping stuff down......... i m a yr 7 and im supposed 2 be asking this !!!!!1

Inside the engine you have pistons attached to rods that are attached with bearings to the crankshaft. The crankshaft has offset points where the rods attach. The pistons are housed in cylinders and on top of the cylinder you have what is called a head. Inside the head are valves that let a fuel and air mixture into the cylinder. The valves are operated by the camshaft which is somehow geared to the crankshaft. As the piston moves up in the cylinder during the compression stroke, the fuel/air is compressed and a spark then ignites the mixture driving the piston down which turns the crankshaft causing one of the other pistons to go up compressing the gas in that cylinder. When this explosion occurs, the piston gets slammed down. That is the power stroke. That causes the crankshaft to turn, sending power to the transmission which in turn allows the car to move. Then the piston returns because of the momentum of the flywheel and the force of the other pistons if there are any. At the same time, a valve opens allowing the burned fuel air mixture to leave the cylinder and flow through the muffler and out the tailpipe. That is the exhaust stroke. Then the exhaust valve closes as the intake valve opens, allowing new fuel mixture to get sucked in during the intake stroke. Then the compression stroke outlined above repeats the entire cycle.

That is pretty basic but it should give you an idea of how it all works. Below are some of the common variations of this.

A diesel engine works similarly, but the detonation is caused by compression rather than ignition. Instead of spark plugs, it is the pressure inside the cylinder which causes the fuel mixture to explode. Fuel injection is required to get the amount of pressure necessary for detonation to occur. Glow plugs are only needed to warm the engine for starting, and a larger starter, battery, and alternator may be required. The cylinder walls might also be thicker. Otherwise the process works pretty much the same as for a 4-stroke gasoline engine.

Then there is the rare Wankel engine that Mazda once used. It contains one or more rotors that have 3 surfaces. There is a rod called an eccentric that functions similarly to the valves of a 4-stroke reciprocating engine. However, a rotary engine is technically a 2-stroke engine since every rotor surface fires once per revolution of the crankshaft, while in a 4-stroke reciprocating engine, the cylinder only fires every other rotation. Anyway, the spark plugs fire and the explosion causes the rotor to rotate, sending the power to the transmission and wheels. Then as the rotor turns the eccentric opens the exhaust port to let the exhaust out and opens the intake port to allow new fuel mixture inside, readying the rotor to fire again once that same surface reaches the same location. The other surfaces fire while the first surface is readied to fire again.

In 2-stroke engines such as in some motorcycles and yard equipment, the pistons also double as valves and both sides of the pistons are involved. So that means that the fuel requires a lubricant to be added since the fuel passes through the crankcase. While the piston is in the power stroke, new fuel air mixture is sucked into the crankcase for the next power stroke. Then ignition occurs, the piston is forced down as part of the power stroke and then the exhaust and intake ports are cleared. As the downward stroke forces new fuel-air-lubricant mixture into the cylinder, the exhaust is cleared, and the piston is again in the compression stroke.

pips are generally cylindrical in structure of amount of heat loss through pipe is given by the formula Q= 2 pi k L(T1-T2)/ln(r2/r1) where k=conductivity of material of which pipe is made T1= temperature of inside layer pipe T2=temperature outside layer of pipe L= length of pipe r1= inner radius r2=outer radius ln=natural logrithem pi=22/7 the above condition applies for steady state flow,single layer over cylinder and neglecting conductivity convection to take conductivity convection into account term Q* must be added Q*=2 pi L{ r1 hi(Ti-T1)+r2 ho(T2-To)} hi=convective coefficient for inside layer ho=convective coefficient for outside layer Ti= temperature of inside space of pipe To=temperature of outside space of pipe for unsteady condition there is another formulaa

The metal spring critically dampens the gun barrel so that it can recoil and the compensate for the reaction of the action done by the bullet.

True

Barber chairs are often raised and lowered using gas or hydraulic struts. These struts work by using strong springs or pressurized gas. Some of these devices can be recharged, or have replaceable seals, but others are disposable items that are replaced as a unit.

carbon,

AISI stands for American Iron and Steel Institute.

The Brooklyn Bridge is one.

思课买地课

no. the Brooklyn bridge is a suspension bridge

why yes, yes you can it wont stain hence the name stainless steel.

Imperial measurements are based on multiples of various numbers eg 16 ozs in a pound, 14 pounds in a stone etc.

Metric measurements are based on multiples of 10 eg 1000 grams in a kilogram etc.

This makes Metric measurements easier to use in calculations.

IS : 2062 - Specification of Steel for General Structural Purposes

CHEMICAL COMPOSITION

Grade C% Max. Mn% Max. S% Max. P% Max. Si% Max. C.E.% Max.

A 0.23 1.50 0.050 0.050 0.40 0.42

B 0.22 1.50 0.045 0.045 0.40 0.41

C 0.20 1.50 0.040 0.040 0.40 0.39

MECHANICAL PROPORTIES

Grade UTS(MPa) Min. Y.S.(MPa) Min. El.% Min. 5.65 Sqrt(So)

Bend

Test

A 410 250 240 230 23 3T

B 410 250 240 230 23 2T & 3T *

C 410 250 240 230 23 2T

* 2T - <= 25mm

* 3T - > 25mm

Assuming the tank is full, the 'head', or pressure expressed in feet of water, is 50 feet at the bottom of the tank. Water weighs 62.4 lb/ft^3. At 50 ft, the pressure is 62.4 X 50 = 3120 lb/ft^2. In lb/in^2, or PSI, the pressure would be 3120/144 = 21.7 PSI, since there are 144 square inches in one square foot. The 4 inch pipe size is irrelevant, unless the water from the tank is flowing through the pipe, the pipe is long, and you are interested in the pressure at the end of the pipe. But you would need more information for that, such as the length of the pipe, the details of any elbows or restrictions, etc.

A turret lathe has six-usual tools arranged in the order of use on a rotating turret which is cycled by a large wheel or (Turnstile) like contrivance- in fact some lathe makers calle them Turnstile lathes. the British prefer the term Capstan lathes, the Capstan being that old extended bar device ( somewhat resembling a turnstile) used by seamen to manually raise the anchor- in old Pirate films, etc. The Capstan or Turnstile is oriented vertically, like a steering wheel. they usually have six stops on a hexagon turret. For this reason, a number of automobile makers had hexagonal trademarks such as Essex and Packard- a mark of homage to the machines used to make the parts!- the Turret Lathe.

Horizontal axis wind turbines, modern wind turbines, vertical axis turbines.

Compression molding starts by inserting plastic or gelatin into a heated mold. Once the material is heated to a pliable state, a hydraulic press compresses the pliable plastic against the mold, which creates a perfectly molded piece. This process is used mostly for manufacturing gears, dinnerwear and electrical parts.

The function of PRV is to supply gas at set pressure as per the design conditions. Suppose the upstream O2 pressure is 30 Bar and we need constant pressure of 12 Bar down stream. So we need a microprocessor controlled PRV to sense the down stream pressure and always it will close or maintain the system pressure to set value of 12 bar.

It is to be noted that initial pressurization to be done very slowly by operating the PRV manually and when the pressure is equal then put it in Auto.

Using various mathematical formulas such as a 45 degree offset would be 1.4142Then there is 90 DEG, 60 Deg, 45 Deg, 22.5 Deg 11 1/4 DEG1/4 bend 1/8 Bend 1/16 Bend 1/32 Bend and then once yo know the angle you want then do the math