The study of waves therefore forms a topic of central importance in all physical science and engineering. 1  The simplest types of wave motion are vibrations of elastic media, such as air, crystalline solids, or stretched strings. If, for example, the surface of a metal block is struck a sharp blow, the deformation of the surface material compresses the metal in the vicinity of the surface, and this transmits the disturbance to the layers beneath.
There are many aromatherapy recipes for treating the symptoms of respiratory infections. Here are a few: For blocked sinuses and tight dry coughs add two drops of eucalyptus radiata essential oil to a bowl of hot water. Drape a towel over the head and lean over the bowl.
Asthma - Asthma may be a cause of a steady cough. It is often accompanied by wheezing and chest tightness, but in some people, a cough is the only symptom. Acid reflux - Gastroesophageal reflux disease (GERD) can result in constant coughing due to the back up of acid from the stomach. A very common cause of coughing, GERD often causes episodes of coughing at night after lying down and often results in hoarseness the following morning.