Positive Displacement Pump (Lobe Pump)

A positive displacement pump causes a fluid to move by trapping a fixed amount of it then forcing (displacing) that trapped volume into the discharge pipe. Positive displacement pumps, unlike centrifugal or roto-dynamic pumps, will produce the same flow at a given speed (RPM) no matter what the discharge pressure.
One practical difference between dynamic and positivedisplacement pumps is their ability to operate under closed valve conditions.
Positive displacement pumps physically displace the fluid; hence closing a valve downstream of a positive displacement pump will result in a continual build up in pressure resulting in mechanical failure of either pipeline or pump. Dynamic pumps differ in that they can be safely operated under closed valve conditions (for short periods of time).
It is called so because replacing equal quantity of liquid from cavity is called positive displacement.

HOW BRAKES STOP VEHICLES

HOW BRAKES STOP VEHICLES

Brakes are an energy-absorbing mechanism that converts vehicle movement into heat while stopping the rotation of the wheels.
All braking systems are designed to reduce the speed and stop a moving vehicle and to keep it from moving if the vehicle is stationary.

Service brakes are the main driver-operated brakes of the vehicle, and are also called base brakes or foundation brakes.
Most vehicles built since the late 1920s use a brake on each wheel. To stop a wheel, the driver exerts a force on a brake pedal. Force on the brake pedal pressurizes brake fluid in a master cylinder.

This hydraulic force (liquid under pressure) is transferred through steel lines and flexible brake lines to a wheel cylinder or caliper at each wheel. Hydraulic pressure to each wheel cylinder or caliper is used to force friction materials against the brake drum or rotor.
The heavier the vehicle and the higher the speed, the more heat the brakes have to be able to absorb.

Long, steep hills can cause the brakes to overheat, reducing the friction necessary to slow and stop a vehicle

Iron Carbon Phase Diagram

GLARE (Glass Laminate Aluminium Reinforced Epoxy)

GLARE (Glass Laminate Aluminium Reinforced Epoxy)

GLARE is a "Glass Laminate Aluminium Reinforced Epoxy" FML, composed of several very thin layers of metal (usually aluminium) interspersed with layers of glass-fibre "pre-preg", bonded together with a matrix such as epoxy. The uni-directional pre-preg layers may be aligned in different directions to suit the predicted stress conditions.

Although GLARE is a composite material,[1] its material properties and fabrication are very similar to bulk aluminum metal sheets. It has far less in common with composite structures when it comes to design, manufacture, inspection or maintenance. GLARE parts are constructed and repaired using mostly conventional metal material techniques.

Its major advantages over conventional aluminium are:
Better "damage tolerance" behaviour (especially impact and metal fatigue, as the elastic strain is larger than other metal material it can consume more impact energy. It is dented easier but has a higher penetration resistance )
Better corrosion resistance
Better fire resistance
Lower specific weight

Furthermore, it is possible to "tailor" the material during design and manufacture such that the number, type and alignment of layers can suit the local stresses and shapes throughout the aircraft. This allows the production of double-curved sections, complex integrated panels or very large sheets, for example.

While a simple manufactured sheet of GLARE will be more expensive than an equivalent sheet of aluminium, considerable production savings can be made using the aforementioned optimization. A structure properly designed for GLARE will be significantly lighter and less complex than an equivalent metal structure, and will require less inspection and maintenance and enjoy a much longer lifetime-till failure, making it a cheaper, lighter and safer option overall.

Applications
Besides the applications on the Airbus A380 fuselage, GLARE has multiple 'secondary' applications. GLARE is also the material used in the ECOS3 blast-resistant Unit Load Device. This is freight container shown to completely contain the explosion and fire resulting from a bomb such as that used over Lockerbie. Other applications include among others the application in the Learjet 45 and in the past also in cargo floors of the Boeing 737.

Current production
GLARE is currently produced by Cytec Engineered Materials in Wrexham, UK who supplies it to the Airbus A380 component manufacturing facilities at Stork Fokker in the Netherlands as well as at Airbus in Nordenham, Germany. Stork Fokker has opened a brand new facility next to its existing facilities in Papendrecht, the Netherlands. There Stork Fokker is able to produce Glare sheets of 4.5 x 11.5 m including the milling of doors windows etc. on a state-of-the-art 5-axis milling machine with a movable bed