Dr Laks says â[e]ven were the regression line to have a slope of zero, if the SD of the duct diameter increases as a function of time, then the upper limit of normal value would increase with age.â There is no indication that the variance increases with age.
PET, which stands for polyethylene terephthalate, is a form of polyester (just like the clothing fabric). It is extruded or molded into plastic bottles and containers for packaging foods and beverages, personal care products, and many other consumer products.ET is a polymer of ethylene glycol and terephthalic acid. Pellets of PET resin are heated to a molten liquid, which can be easily extruded or molded into almost any shape. PET was first synthesized in the U.S. during the mid-1940s by DuPont chemists searching for polymers that could be used to make new textile fibers.
PET stands for PolyEthylene Terephthalate and is sometimes referred to as PETE, PETP, or PET-P. PET is a thermoplastic polymer in the polyester family that is formed by combining two types of monomers together; ethylene glycol and purified terephthalic acid. major use of Polyethylene Terephthalate is in synthetic fibers used for manufacturing polyester clothing, fabrics, carpets, etc. PET used for this purpose consumes more than 60% of PET usage worldwide!