The Diesel cycle is a combustion process of a reciprocating internal combustion engine. In it, fuel is ignited by heat generated during the compression of air in the combustion chamber, into which fuel is then injected. This is in contrast to igniting the fuel-air mixture with a spark plug as in the Otto cycle (four-stroke/petrol) engine. Diesel engines are used in aircraft, automobiles, power generation, diesel-electric locomotives, and both surface ships and submarines.
ETA, an acronym for Euskadi Ta Askatasuna, was an armed leftist Basque nationalist and separatist organization in the Basque Country. The group was founded in 1959 and later evolved from a group promoting traditional Basque culture to a paramilitary group engaged in a violent campaign of bombing, assassinations and kidnappings in the Southern Basque Country and throughout Spanish territory. Its goal was gaining independence for the Basque Country. ETA was the main group within the Basque National Liberation Movement and was the most important Basque participant in the Basque conflict.
A jet engine is a type of reaction engine discharging a fast-moving jet that generates thrust by jet propulsion. This broad definition includes airbreathing jet engines. In general, jet engines are combustion engines.
An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile engines.
In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media when the force of gravity or buoyancy tries to restore equilibrium. An example of such an interface is that between the atmosphere and the ocean, which gives rise to wind waves.
A jet aircraft is an aircraft propelled by jet engines.
A railway air brake is a railway brake power braking system with compressed air as the operating medium. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on April 13, 1869. The Westinghouse Air Brake Company was subsequently organized to manufacture and sell Westinghouse's invention. In various forms, it has been nearly universally adopted.
The vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became almost universal in British train equipment and in countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in the United States, primarily on narrow-gauge railroads. Its limitations caused it to be progressively superseded by compressed air systems starting in the United Kingdom from the 1970s onward. The vacuum brake system is now obsolete; it is not in large-scale usage anywhere in the world, other than in South Africa, largely supplanted by air brakes.
Regenerative braking is an energy recovery mechanism which slows a vehicle or object by converting its kinetic energy into a form which can be either used immediately or stored until needed. In this mechanism, the electric motor uses the vehicle's momentum to recover energy that would be otherwise lost to the brake discs as heat. This contrasts with conventional braking systems, where the excess kinetic energy is converted to unwanted and wasted heat by friction in the brakes, or with dynamic brakes, where energy is recovered by using electric motors as generators but is immediately dissipated as heat in resistors. In addition to improving the overall efficiency of the vehicle, regeneration can greatly extend the life of the braking system as its parts do not wear as quickly.
ETA Systems was a supercomputer company spun off from Control Data Corporation (CDC) in the early 1980s in order to regain a footing in the supercomputer business. They successfully delivered the ETA-10, but lost money continually while doing so. CDC management eventually gave up and folded the company.
The ETA10 is a line of vector supercomputers designed, manufactured, and marketed by ETA Systems, a spin-off division of Control Data Corporation (CDC). The ETA10 was announced in 1986, with the first deliveries made in early 1987. The system was an evolution of the CDC Cyber 205, which can trace its origins back to the CDC STAR-100.
The estimated time of arrival (ETA) is the time when a ship, vehicle, aircraft, cargo, emergency service or person is expected to arrive at a certain place.
Eta is the seventh letter of the Greek alphabet
David Alexander Wolf is an American astronaut, medical doctor and electrical engineer. Wolf has been to space four times. Three of his spaceflights were short-duration Space Shuttle missions, the first of which was STS-58 in 1993, and his most recent spaceflight was STS-127 in 2009. Wolf also took part in a long-duration mission aboard the Russian space station Mir which lasted 128 days, and occurred during Mir EO-24. He was brought to Mir aboard STS-86 in September 1997, and landed aboard STS-89 in January 1998. In total Wolf has logged more than 4,040 hours in space. He is also a veteran of 7 spacewalks totaling 41hrs 17min in both Russian and American spacesuits.
The 2004 Madrid train bombings were nearly simultaneous, coordinated bombings against the Cercanías commuter train system of Madrid, Spain, on the morning of 11 March 2004 – three days before Spain's general elections. The explosions killed 193 people and injured around 2,000. The bombings constituted the deadliest terrorist attack carried out in the history of Spain and the deadliest in Europe since the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland. The official investigation by the Spanish judiciary found that the attacks were directed by an al-Qaeda terrorist cell, although no direct al-Qaeda participation has been established. Although they had no role in the planning or implementation, the Spanish miners who sold the explosives to the terrorists were also arrested.
The end of train device (ETD), sometimes referred to as an EOT, flashing rear-end device (FRED) or sense and braking unit (SBU) is an electronic device mounted on the end of freight trains in lieu of a caboose. They are divided into three categories: "dumb" units, which only provide a visible indication of the rear of the train with a flashing red taillight; "average intelligence" units with a brake pipe pressure gauge; and "smart" units, which send back data to the crew in the locomotive via radio-based telemetry. They originated in North America, and are also used elsewhere in the world, where they may include complete End of Train Air System (ETAS) or Sense and Brake Unit (SBU) devices.
In thermodynamics, the thermal efficiency is a dimensionless performance measure of a device that uses thermal energy, such as an internal combustion engine, a steam turbine or a steam engine, a boiler, furnace, or a refrigerator for example. For a heat engine, thermal efficiency is the fraction of the energy added by heat that is converted to net work output. In the case of a refrigeration or heat pump cycle, thermal efficiency is the ratio of net heat output for heating, or removal for cooling, to energy input.
In aircraft and rocket design, overall propulsive efficiency is the efficiency with which the energy contained in a vehicle's propellant is converted into kinetic energy of the vehicle, to accelerate it, or to replace losses due to aerodynamic drag or gravity. It can also be described as the proportion of the mechanical energy actually used to propel the aircraft. It is always less than one, because conservation of momentum requires that the exhaust have some of the kinetic energy, and the propulsive mechanism is never perfectly efficient. Overall propulsive efficiency is greatly dependent on air density and airspeed.
Visitors to Sri Lanka visiting for tourism purposes must obtain an Electronic Travel Authorization (ETA), unless they are exempt, prior to arrival or on arrival to Sri Lanka or they must obtain a visa in advance. All visitors must hold a passport valid for 6 months. Nationals of Afghanistan, Iran, Iraq, Nigeria, Pakistan, Somalia and Syria must hold return or onward tickets. Visitors are strongly urged to use the online system to avoid lengthy delays at the port of entry.
