Usually, the egg will be implanted between 6 to 12 days of egg retrieval. After five days of embryo transfer, the egg reaches blastocyst stage. For accuracy, you need to county the day of retrieval as day 0.
A motor car engine is an Internal Combustion Engine (ICE). Energy is created by burning either diesel or petrol in a combustion chamber. In such an engine, the energy is transferred from the pistons moving up and down at high speeds. This up-down motion is converted to a rotary motion through the crankshaft and axle.
When no signal is received from the O2 sensor, as is the case when a cold engine is first started (or the 02 sensor fails), the computer orders a fixed (unchanging) rich fuel mixture. This is referred to as open loop operation because no input is used from the O2 sensor to regulate the fuel mixture.