Sinusitis is an inflammation of the sinuses. It is often caused by bacterial (germ) infection. Sometimes, viruses and fungi (molds) cause it. People with weak immune systems are more likely to develop bacterial or fungal sinus infection. Some people with allergies can have allergic fungal sinus infection. Acute sinus infection lasts three to eight weeks. A sinus infection lasting longer than eight weeks is considered chronic.
Define Upper stage. Upper stage synonyms, Upper stage pronunciation, Upper stage translation, English dictionary definition of Upper stage. n. A rocket composed of two or more propulsion units that fire in succession. Also called step rocket . Noun 1. multistage rocket - a rocket having two or...
The word upper indicates that the UCST is an upper bound to a temperature range of partial miscibility, or miscibility for certain compositions only. For example, hexane-nitrobenzene mixtures have a UCST of 19 Â°C, so that these two substances are miscible in all proportions above 19 Â°C but not at lower temperatures. solid state example is the palladium-hydrogen system which has a solid solution phase (H 2 in Pd) in equilibrium with a hydride phase (PdH n) below the UCST at 300 Â°C. Above this temperature there is a single solid solution phase.