Mechanical Engineering

That is called boiling.

And it is something you can see and observe, but it is something tht is chemically relted and so it is a chemical change.

A metallurgist

Reciprocating compressors are positive displacement in machines. However, separable compressors have higher maintenance costs.

THREE CLASSES OF LEVER There are three classes of lever and each class has fulcrum, load and effort which together can move a heavy weight. CLASS 1 The workman uses a trolley to move the large packing case. The fulcrum is the wheel. CLASS 2The gardener uses a wheel barrow to lift tools and garden waste. The load is in the centre of the barrow CLASS 3 The fisherman catches the fish which becomes the load at the end of the lever.

Second order derivative is used in many fields of engineering. One of its application is used in solving problems related to dynamics of rigid bodies and in determination of forces and strength of materials.

A dynamic load arises from the acceleration or deceleration of a "static" load (mass). A shock load occurs when this acceleration or deceleration is very large and the the time frame is very short.

Depending on the context it could be:

EPR Emergency Preparedness and Response (US DHS)

EPR Electron Paramagnetic Resonance

EPR Electronic Patient Record(s)

High carbon steel is stronger than low carbon steel with proper heat treatment. Thus, it will fail at a much higher load.

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Note: not all shear pins are high carbon heat treated steel. The pin needs to be nearly as strong, but not stronger than the material in which it is used, so that it shears off before the material it protects is damaged. thus a shear pin for a bronze shaft may actually be made of copper. Obviously the stronger the material, or larger the diameter of the pin, the more load it can handle, but it needs to shear off before the material it protects is crushed. I'd assume that a high carbon steel shear pin is being used on a machine made of some high tensile strength stainless alloy.

BS 4190 confirm equivalent of DIn

The important point in feer gauges ( also called thickness gages by some of the manufacturers ) is the thickness of the blades. Therefore in order to calibrate a feeler gauge you need to measure the thickness of the gauge at various locations along the length of the device. The standard used in the calibration should satisfy a TUR ( Test Uncertainty Ratio ) of at least 4:1 in order to limit the FAR ( False Accept Risk ) to nearly 2%. Such devices do not require periodic calibration. However, they should be standardized before every use by a standard in order to assure reliable measurements.

A type of reciprocating/positive displacement compressor in which the gas is compressed using a piston cylinder that is connected to a crankshaft. As a result of the flywheel rotation, the crankshaft moves the piston causing it to compress the air. The most common application for such type of compressors are the internal combustion engines

After problem solving solutions have been exhausted eg: Advice was sought. Supporting literature was read. Procedural steps had been taken and have proved unsuccessful. Your line/dept manager should be informed.

Mechanical Engineering is a discipline of engineering that applies the principles of engineering, physics and material sciences for analysis, design, manufacturing and maintenance of mechanical systems. It involves the production and usage of heat and mechanical power for the design, production and operation of machines and tools.

i dont know how but i know that engineering industries do!

sorry... dont know anymore

peace....

i ♥ zain malik

To manage and supervise all the work done in an construction site, also to give work orders for work in his site by mean of the drawings received from the designer and maintain the quality of work due to those received drawings

steel

A weld symbol is the shape drawn on a Print to tell the welder: how to prepare a welding joint, what process can be used to weld (mig, tig, arc, etc) what filler rod to use, how wide and long the weld should be, how to deal with the weld after your done (grind flush, brush clean, or nothing) and a million other things....

Its a tool that design engineers use to communicate what the weld needs to be to meet their design specifications.

Mechanical Efficiency is the ratio of Actual mechanical advantage to ideal mechanical advantage.Efficiency will be maximum when Actual mechanical advantage equals that of ideal.But practically not possible.Actual mechanical advantage will be less due to friction,heat,deflection etc.avoiding these loses will increase the machine efficiency.

CLEANING

Cleaning was one of the earliest industrial applications of ultrasonics. Objects to be cleaned are placed in a bath of fluid which is violently agitated by a number of ultrasonic transducers. The fluid may be water or solvent based, depending on the application. Traditionally the transducers were fitted around the walls of the cleaning bath, but some modern equipment uses an external transducer attached to a resonant probe which transmits the vibrations to the fluid.

The ultrasonics may affect the cleaning process in several ways. Rapid movement in the fluid can help to de-wet surfaces, overcoming surface tension, and may also help to dislodge dirt particles and carry them away from the surface. Cavitation is probably the most interesting (and potent) effect - the shock waves generated by tiny implosions of vapour bubbles can be devastating at close range. The bubbles are so tiny that they can penetrate even the smallest crevices, making the process ideal for parts which could not be cleaned by other methods. Note also that the process must be well controlled to minimise erosion of the surfaces of the parts being cleaned. The standard test of ultrasonic intensity in a cleaning bath is to immerse a standard foil strip for a set time, then remove it and count the number of holes!

CUTTING

Imagine a knife which moves itself backwards and forwards in a sawing action, thirty thousand times a second. True the distance moved is very small but the acceleration is so high that nothing can move with the blade or stick to it. Ultrasonic scalpels are used by surgeons where they want to cut without exerting any pressure. In industry ultrasonic cutting tools are used for products that are difficult to cut by other means.

The heat generated by the ultrasonic vibrations can also be useful. Some man-made fabrics are cut and simultaneously sealed using ultrasonic knives to prevent fraying.

ULTRASONIC MACHINING

Ultrasonics have been used in several ways for machining metals. Lathe tools may benefit from deliberately-induced vibrations to prevent "chatter" which compromises the surface finish of the finished component. Ultrasonic drills, used on very hard ceramics, work by grinding or eroding material away - a liquid slurry around the drill bit contains loose hard particles which are smashed into the surface by the vibrations, eroding material away and creating more loose hard particles

METAL FORMING

My own experience of power ultrasonics is mainly in this field. CarnaudMetalbox R&D (now a part of Crown Cork and Seal - the biggest packaging company in the world) and Loughborough University developed a new aerosol can using a number of novel metal-forming processes, starting with ultrasonic necking (i.e. reducing the diameter of the can at one end). The advantage of using ultrasonics in this case was to minimise friction between the can and the die, thus reducing the forming force. Without ultrasonics the force was so high that the can body would buckle and collapse during the necking process. With ultrasonics a 30% reduction in can diameter could be achieved in a single operation (in conventional necking processes the maximum is typically about 5%).

The ultrasonics were only effective when the vibrations were perpendicular to the surface - for a cylindrical can this meant developing a round die that would vibrate in the radial direction. As with other high-power applications, all tooling had to be resonant, so the desired mode of resonance was a uniform hoop expansion / contraction. We quickly found that while it was fairly easy to design a die to resonate in this mode at the frequency of the ultrasonic equipment, excluding other modes of vibration was a major challenge!

Another difficulty was that with the whole die expanding and contracting there was no convenient nodal (stationary) point which could be used for mouning it. This was solved by the use of a tubular mounting system which was itself resonant at the same frequency as the die.

The ultrasonic forming process went into production making small-diameter aerosol cans in a UK factory. The production line still runs intermittently, making promotional packaging for several prominent customers. One of its products ("Fleurs de Paris" parfum deospray can) won a silver in the 1997 Metal Packaging Manufacturers Association awards.

METAL WELDING

. Ultrasonics can be used to weld different metals together, without solder and flux or special preparation. The process is different to plastic welding in that the two components are vibrated parallel to the interface. This is a more intuitively logical method of generating friction between them, but frictional heating is not thought to be the prime mechanism of the process - the temperature needed to melt (or even soften) most metals would be very difficult to achieve. Instead the mechanism is thought to be diffusion-bonding: atoms of each part diffuse into the other when the two surfaces are brought together in close contact. The ultrasonics promotes this close contact by breaking down the surface oxide layers, allowing the "raw" metals to make contact.

The process has some limitations. It is only suitable for relatively small components (a prime example is welding connectors to car battery leads) since the power required to weld larger parts would be higher than can practically supplied by this method. Also the process tends to mark and deform the components, since high clamping forces and sonotrodes with serrated working faces must be used to grip the workpiece firmly.

PLASTIC WELDING

Plastic welding is used for a huge variety of products ranging from blister packs, cartons and small consumer goods up to car fuel tanks and dashboards. It works by generating heat exactly where it is needed - at the interface between the components to be joined. The components are clamped between a vibrating sonotrode and a fixed mounting. Strangely, the vibrations are usually applied perpendicular to the contact surface, although much of this vibration may be converted to in-plane movement. This also has the advantage that the clamping pressure will keep the sonotrode in contact with the component - serrated surfaces are generally not required. Best results are achieved when the components are clamped close to the interface ("near-field" welding) but if this is not possible then the process can still work at a distance ("far-field").

Staking, or insertion, is a variation of this process in which a metal part (generally a threaded bush) is driven into a hole in a plastic component, which then solidifies around it to form a permanent join. This is a convenient method of producing strong tapped holes in a plastic part.

More information:

SIEVING

Industrial sieves are normally agitated at low frequency to help the product to distribute itself evenly over the surface and to help the small particles go through. Vibrating the mesh at ultrasonic frequencies (in addition to this low-frequency oscillation) can improve the rate of flow dramatically, preventing the product from blocking the holes in the mesh and helping to separate the small particles from the large.

SINTERING

The powder-metallurgy process is used to manufacture top-quality steels and other metals. The powder must be packed as closely as possible before the sintering process begins to prevent the formation of voids or other weaknesses in the finished product. Published research papers indicate that a significant increase in the packing density can be achieved using ultrasonics. Can anyone confirm that this process is in production?

A light sensor shines a light on the image to be scanned and collects the data as simple changes between black and white based on the level of reflection. These changes are later converted into digital form for processing.

i have the same question on my drafting pre-test. the answer is unidirectional.

There are several ways to calculate the .steam consumption rate. First would be to use a heat transfer equation. Another way would be to measure steam directly using flow metering equipment.

speed is the ratio of the distance an object moves per time unit (seconds,minutes hours)

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