Elysse Bell is a finance and business writer for Investopedia. She writes about small business, personal finance, technology, and more. Erika Rasure is globally-recognized as a leading consumer ...

Abstract: Due to the energy conservation law, traditional active noise control system cannot realize the suppression of omnidirectional sound field and will bring fluctuation effect in the far field.

Abstract: Metamaterials (MMs) are synthetic composite structures with superior properties not found in naturally occurring materials. MMs have gained massive attention over the last two decades ...