To detect heart sounds, the patient should be lying down and examined in a quiet room. Left-sided S3 is best heard at the apex of the heart (the lower pointed end of the heart) with the patient lying on his left side. It is a low-pitched sound and heard best using the bell of the stethoscope with light pressure.
Adorable animal families that will make you aww. Polystyrene is a type of polymer with thermoplastic properties produced from the petroleum-derived monomer, styrene. In solid form, it is a colorless and rigid plastic, but it may also be returned to a liquid state by heating, and used again for molding or extrusion.
Many call it Styrofoam, though that term is actually the brand name of a rigid blue insulation made by Dow Chemical Company. Polystyrene is a very versatile material, but recycling it isn't always easy. The term polystyrene means that the plastic is derived from styrene, a liquid hydrocarbon. When heated, monomer styrene molecules link together into long chains, creating a polymer material that's solid when it cools to room temperature.