reverse osmosis desalination Cartridge filters

Define glass transition temperature in polymeric materials and name two parameters ineach case that can change it.

Given the table below and your judgement for extreme operational conditions, select polymers for the following applications respectively: a dry ice bucket (operating temperature of -78C), a teeth aligner, a hair dryer (operating temperature range of 60-80C) and a phone case. Table 15.2 Melting and Glass Transition Temperatures for Some of the More Common Polymeric Materials Material Polyethylene (low density) Polytetrafluoroethylene Polyethylene (high density) Polypropylene Nylon 6,6 Polyester (PET) Poly(vinyl chloride) Polystyrene Polycarbonate Glass Transition Temperature [°C (°F)] -110 (-165) -97 (-140) -90 (-130) -18 (0) 57 (135) 69 (155) 87 (190) 100 (212) 150 (300) a. Polypropylene, PET, PTFE, Polypropylene O b. PTFE, HDPE, HDPE, polypropylene c. LDPE, PTFE, Nylon, polypropylene O d. Nylon, PET, HDPE, PVC Oe. HDPE, LDPE, LDPE, PTFE Melting Temperature [°C (°F)] 115 (240) 327 (620) 137 (279) 175 (347) 265 (510) 265 (510) 212 (415) 240 (465) 265 (510)

What are the four elements of corrosion cell ? Give brief description for each of the element.