Secondary Waves Defined. Secondary waves, or S-waves, are seismic waves produced by an earthquake. As one side of a fault slips past the other, the pressure that had been stored is released and travels radially away from the focus of the earthquake.
Non-Absorbable sutures include :- Polypropylene sutures, Nylon (poylamide), Polyester, PVDF, silk and stainless steel sutures. Monofilament and Multifilament Sutures. Sutures can also be divided into two types on the basis of material structure i.e. monofilament sutures and multifilament or braided sutures. Braided sutures provide better knot security whereas monofilament sutures provide better passage through tissues.
Most commercial polypropylene is isotactic and has an intermediate level of crystallinity between that of low-density polyethylene (LDPE) and high-density polyethylene (HDPE). Polypropylene is normally tough and flexible, especially when copolymerized with ethylene.hen the methyl groups in a polypropylene chain exhibit no preferred orientation, the polymers are called atactic. Atactic polypropylene is an amorphous rubbery material. It can be produced commercially either with a special type of supported Ziegler-Natta catalyst or with some metallocene catalysts.