Mechanical Engineering

A very good periodic table. See the Web Links to the left of this answer for a periodic table with melting and boiling points, and other tables with the melting and boiling points of the elements. Go to this awesome site: HTTP://WWW.MATWEB.COM and find most any comercially-available material (all metals, plastics & ceramics). You can sort by property, which makes it easy to find the best material for your application.

Its not only about rotor, Core losses of every machine which has core are fixed and only vary with Voltage variation.

A rubber band boat works much like a rubber band airplane. First you need to build the boat itself. Then you need to make a propeller. The propeller shaft needs to run through the inside of the boat, not below the boat. With the prop below the water. The propeller shaft should not go the full length of the boat. About halfway through put a loop in the shaft. Then to the front of the boat attach a rubber band. Then run the rubber band through the loop in propeller shaft. Now twist the prop and the rubber band should twist around and around. When it's good and tight let go and the propeller should spin. Allowing the boat to move forward in the water.

Mind you the shaft needs to be a thin piece of metal, as it will be difficult to make it water tight.

High pressure (HP) and Low pressure (LP) bypass systems are used for quick start-up of the unit as well as during trip-out, where load rejection at the turbine does not automatically lead to a boiler trip. With a bypass system, start-up is quicker. The system diverts the steam generated by the boiler to the Re-heater/Condenser, at the same time reducing the pressure and temperature of steam, thus maintaining a minimum circulation of steam through the boiler. This enables running the boiler without the turbine in service, ensuring flow through re-heater coils.

HP-LP bypass system has the following advantages :-

1.The prolonged venting of safety valves to atmosphere is avoided, thereby reducing DM water loss and cutting noise emission.

2.Sustained flow through the boiler heating surfaces is assured, ensuring Re-heater protection during start-up of units.

3.If the grid cannot accept power, the unit can be kept running on house load.

Only if it has a WOG rating that is with in the design of the system

because it is the ratio of the stress to the strain and in actual condition the strain developed is different from the theoretical .

It is nowadays used in Malls , shopping Complexes as a purpose for thermometric billing ,It measures the Quantum of Heat that is Used by the respective shop getting Chilled water supply to its AHU/FCU from a Centrally placed Water Chilling Unit (CHiller) which the owner of building has placed.

It is like an electricity Consumption meter In this case measuring Heat in BTU

Regards

Rakesh Baurai

http://sankrantee.blogspot.com

Constructin:

It works like an optical spectometer.X-rays frm an Xray tube are incedent on a crystal at some glancing angle 'b'.Since they r to be incedented in form of narrow beams slits of lead plates are used.the crystal is mounted on a turntabe which can move along a vertical axis.circular scales are mounted on the turntable to measure the ange'b'.At some point it consists of an arm which has a detector attached to it.when the turntablle moves with an ange'b' the arm moves with angle 2b.this way the X-ray beam is always incidented inside the detector.The ionising current produced by the reflected beam is merasured by a sensitive electometer E or recorded on photographic plates.

Working:

Initially the angle b is adjusted to 0 deg.With this the detector is so adjusted to receive the beam inside it.Then the crystal is moved in small angles and the correspnding deflections is noted down.A graph is ploted of Ionization current vs glancing ange.

This is used to verify Bragg's law.

ie sin a:sin b:sin c=1:2:3.

It is important to heat treat in vacuum as otherwise lots of oxides form; after heat treat in vacuum oxides are removed, if part small enough, by use of an abrasive grit pad, such as Scothbrite A, and cleaned with acetone followed by isopropyl alcohol. If not protected, however, oxides will continue to form in air

In order to calculate the internal capacity of a pipe use the formula pi x internal radius x internal radius x length of pipe where pi = 3. 142. This is the volume of a cylinder; pipe capacity is usually amount of flow per unit of time under given conditions of internal roughness, and viscosity of the flowing fluid with a given pressure loss per length unit

unc is coarse, unf is fine pitch

An additional turning moment is caused by movement away from the pivot, and will try to cause the crane to rotate in the direction of the load. (As on a see-saw, weight farther from a fulcrum exerts a larger moment in moving over a longer distance.) Unless the counterweight is also extended (in the opposite direction), the force will be applied to lifting up on the base of the crane, on the side away from the load. At the same time, the center of gravity is changed, and more of the total weight (crane and load) is shifted at the base, toward the side of the load. You can easily demonstrate this by lifting a heavy object and then extending it away from your body. The weight will shift from your heels to your toes and lean you forward.

The glass transition temperature of Nylon 66 is typically around 50-60°C. This is the temperature at which the material transitions from a hard, glassy state to a softer, rubbery state.

Before the electric drill , it was done by hand.

There's a hand-cranked drill, probably still used by the Amish. My father owned one.

The gas (working fluid) having flown through the turbine does some work on the turbine, converting its thermal energy into mechanical work produced by the turbine and coming out as an expanding gas with lower temperature and pressure.

it is a tool that is used to hold materials whilst drilling.

It began roughly with the discovery of the simple machines. Those are the basis for all modern day machines. It also evolved as ancient societies sought to build larger and larger structures. It could be argued it came into its present day form during the industrial revolution. Also very important was the discovery of the relationship between electricity and magnetism, that allowed the development of motors, a tool of incredible importance to the ME's work and our lives.

the maximum stress which the material can bear without breaking is called the maximum tensile strength of the material

There is no simple answer to this. It depends on the weight and hydrodynamics of the hull and the horsepower and rpm of the engine. It also depends on how you want the boat to perform. For a ski-boat, you want a lot of power "out of the hole", for a speed-boat you might want top end performance. As a general rule, boat manufacturers pick a prop that puts the same power into the water that the engine is capable of producing at wide open throttle. Check with the boat manufacturer or dealer for recommendations. Other than that, the only way is to experiment with different props.

Power is energy divided by time, P=E/t.

To support the molten metal while it is cooling

in cnc we have to change the tool for different operations in vmc automatic change of tool is done