Seawater typically has a salinity of around 35 g/kg, although lower values are typical near coasts where rivers enter the ocean. Rivers and lakes can have a wide range of salinities, from less than 0.01 g/kg to a few g/kg, although there are many places where higher salinities are found.onceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sodium bicarbonate which dissolve into ions.
Palatal Expansion. Palatal expansion is a combination of tooth movement and jaw expansion. It works by widening the two halves of the upper jaw, called the palate. The two halves are joined together by a 'suture' in the middle of the roof of the mouth.
Treatment. Treatment of cleft palate and cleft lip is by surgery, followed by measures to improve speech. A cleft palate should be reconstructed by plastic surgery when the child is about 18 months old, before he learns to talk. The corrective work usually requires only one operation.