rigorous (Adjective). Manifesting, exercising, or favoring rigour; allowing no abatement or mitigation; scrupulously accurate; exact; strict; severe; relentless; as, a rigorous officer of justice; a rigorous execution of law; a rigorous definition or demonstration. rigorous (Adjective). Severe; intense; inclement; as, a rigorous winter.
Polylactic acid or polylactide (PLA, Poly) is a biodegradable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States and Canada), tapioca roots, chips or starch (mostly in Asia), or sugarcane (in the rest of the world).eing able to degrade into innocuous lactic acid, PLA is used as medical implants in the form of anchors, screws, plates, pins, rods, and as a mesh. Depending on the exact type used, it breaks down inside the body within 6 months to 2 years.
Bisphenol A (BPA) is an industrial chemical used to make polycarbonate plastic resins, epoxy resins, and other products. Bisphenol A (BPA) is a chemical building block that is used primarily to make polycarbonate plastic and epoxy resins.Polycarbonate plastic is a lightweight, high-performance plastic that possesses a unique balance of toughness, optical clarity, high heat resistance, and excellent electrical resistance.afety assessments of bisphenol A (BPA) conclude that the potential human exposure to BPA from polycarbonate plastics and epoxy resins is more than 400 times lower than the safe level of BPA set by the U.S. Environmental Protection Agency.