The BUN is roughly one-half of the blood urea (R). Normal human adult blood should contain between 5 to 20 mg of urea nitrogen per 100 ml (5â20 mg/dL) of blood, or 1.8 to 7.1 mmol urea per liter (R). To convert from mg/dL of blood urea nitrogen to mmol/L of urea, multiply by 0.357.
The 'dark' side of the moon. The moon orbits the Earth once every 27.322 days. It also takes approximately 27 days for the moon to rotate once on its axis. As a result, the moon does not seem to be spinning but appears to observers from Earth to be keeping almost perfectly still. Scientists call this sychronous rotation. The side of the moon that perpetually faces Earth is known as the near side. The opposite or back side is the far side.
The time taken for the Moon to spin on its axis is almost exactly the same as the time it takes to orbit the Earth. Hence, the Moon always keeps the same side pointing our way. This is not a coincidence. Over billions of years, the Earthâs gravity has forced the Moon to spin synchronously with its orbit. However, things are a bit more complicated than that.