Some facts - Alternatives to car use
Established alternatives for some aspects of car use include public transit such as buses, trolleybuses, trains, subways, tramways light rail, cycling, and walking. Car-share arrangements and carpooling are also increasingly popular, in the US and Europe.75 For example, in the US, some car-sharing services have experienced double-digit growth in revenue and membership growth between 2006 and 2007. Services like car sharing offering a residents to "share" a vehicle rather than own a car in already congested neighborhoods.76 Bike-share systems have been tried in some European cities, including Copenhagen and Amsterdam. Similar programs have been experimented with in a number of US Cities.77 Additional individual modes of transport, such as personal rapid transit could serve as an alternative to cars if they prove to be socially accepted.
Agricultural machinery - monuments
Automobile is not only cars or motorbikes. Many fans machine collects all sorts of completely different equipment. They are often used to actively vehicles participating in field work. The use of such machines was quickly superseded by more modern equipment, but their nature has not changed. Often these age machines are really worth huge sums of money, and not everyone can afford to buy these stylish devices. Many of them are still working and fulfills its functions in the field. Many agricultural machines from different periods only takes on its value, and for collectors is a real gem. No wonder that organized various meetings and rallies for fans of old tractors, combines and so on.
Diagram showing the operation of a 4-stroke SI engine
Main article: 4-stroke engine
Diagram showing the operation of a 4-stroke SI engine. Labels:
1 ? Induction
2 ? Compression
3 ? Power
4 ? Exhaust
The top dead center (TDC) of a piston is the position where it is nearest to the valves; bottom dead center (BDC) is the opposite position where it is furthest from them. A stroke is the movement of a piston from TDC to BDC or vice versa together with the associated process. While an engine is in operation the crankshaft rotates continuously at a nearly constant speed. In a 4-stroke ICE each piston experiences 2 strokes per crankshaft revolution in the following order. Starting the description at TDC, these are:78