high emissions History of electric motor
Perhaps the first electric motors were simple electrostatic devices created by the Scottish monk Andrew Gordon in the 1740s.2 The theoretical principle behind production of mechanical force by the interactions of an electric current and a magnetic field, Amp?re's force law, was discovered later by André-Marie Amp?re in 1820. The conversion of electrical energy into mechanical energy by electromagnetic means was demonstrated by the British scientist Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury, on which a permanent magnet (PM) was placed. When a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire.3 This motor is often demonstrated in physics experiments, brine substituting for toxic mercury. Though Barlow's wheel was an early refinement to this Faraday demonstration, these and similar homopolar motors were to remain unsuited to practical application until late in the century.
Jedlik's "electromagnetic self-rotor", 1827 (Museum of Applied Arts, Budapest). The historic motor still works perfectly today.4
In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils. After Jedlik solved the technical problems of the continuous rotation with the invention of the commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for instructional purposes, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator, rotor and commutator. The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings
Źródło: https://en.wikipedia.org/wiki/Electric_motor
Outlined car
One of the most common problems, which has to face many a owner of such a vehicle such as a car or a motorcycle, a scratch on the car paint. We can scratch the car in just a few moments, without using even this sharp tool. Many scratches formed, for example, the inability of parking or reversing. Unfortunately, many of them are also the result of actions of hooligans, we leave the car, for example, in the wrong neighborhood. How to deal with such a problem? Of course, in many cases it is necessary to visit the factory paint. In smaller straches it may be useful to also use, for example, with a special pen that allows at least a little to mask the resulting defects.
2-stroke engines
2-stroke engines
Main article: 2-stroke engine
The defining characteristic of this kind of engine is that each piston completes a cycle every crankshaft revolution. The 4 processes of intake, compression, power and exhaust take place in only 2 strokes so that it is not possible to dedicate a stroke exclusively for each of them. Starting at TDC the cycle consist of:
Power: While the piston is descending the combustion gases perform work on it?as in a 4-stroke engine?. The same thermodynamic considerations about the expansion apply.
Scavenging: Around 75° of crankshaft rotation before BDC the exhaust valve or port opens, and blowdown occurs. Shortly thereafter the intake valve or transfer port opens. The incoming charge displaces the remaining combustion gases to the exhaust system and a part of the charge may enter the exhaust system as well. The piston reaches BDC and reverses direction. After the piston has traveled a short distance upwards into the cylinder the exhaust valve or port closes; shortly the intake valve or transfer port closes as well.
Compression: With both intake and exhaust closed the piston continues moving upwards compressing the charge and performing a work on it. As in the case of a 4-stroke engine, ignition starts just before the piston reaches TDC and the same consideration on the thermodynamics of the compression on the charge.
While a 4-stroke engine uses the piston as a positive displacement pump to accomplish scavenging taking 2 of the 4 strokes, a 2-stroke engine uses the last part of the power stroke and the first part of the compression stroke for combined intake and exhaust. The work required to displace the charge and exhaust gases comes from either the crankcase or a separate blower. For scavenging, expulsion of burned gas and entry of fresh mix, two main approaches are described: Loop scavenging, and Uniflow scavenging, SAE news published in the 2010s that 'Loop Scavenging' is better under any circumstance than Uniflow Scavenging.6
Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine