Abstract: An antimicrobial air treatment device and a method of its construction. The antimicrobial air treatment device comprises an antimicrobial metal nanoparticle mesh comprising a steel support mesh and a layer of copper nanoparticles disposed on the steel support mesh. The antimicrobial air treatment device may be in the form of a facemask or a component of a moving air filtration system such as an HVAC system, an automobile cabin air filtration system, and an air purifier. The antimicrobial air treatment device may contain one or more filtration layers of filtration medium. The method of constructing the antimicrobial air treatment device involves the preparation of the antimicrobial metal nanoparticle mesh by an electrodeposition technique.

Abstract: The method of increasing the hardness of wurtzite crystalline materials is directed to the production of tool bits and inserts having a hardness approaching that of diamond, while simultaneously providing greater toughness and fracture resistance than diamond. The method includes forming a workpiece of boron nitride having a wurtzite crystal structure (wBN), and optionally combining boron nitride having a cubical crystal structure (cBN) with the wBN material. The workpiece is heat-treated by a defocused laser beam moved across the surface at a rate sufficient to preclude melting or deformation of the workpiece. The heated area is quickly quenched by a water jet, and a gas jet immediately follows the laser path to assure separation of the water from the laser contact area. The result is an increase in hardness of about 88%, from an initial hardness of about 40 GPa to a treated hardness of about 75 GPa.

Abstract: The method of increasing the hardness of wurtzite crystalline materials is directed to the production of tool bits and inserts having a hardness approaching that of diamond, while simultaneously providing greater toughness and fracture resistance than diamond. The method includes forming a workpiece of boron nitride having a wurtzite crystal structure (wBN), and optionally combining boron nitride having a cubical crystal structure (cBN) with the wBN material. The workpiece is heat-treated by a defocused laser beam moved across the surface at a rate sufficient to preclude melting or deformation of the workpiece. The heated area is quickly quenched by a water jet, and a gas jet immediately follows the laser path to assure separation of the water from the laser contact area. The result is an increase in hardness of about 88%, from an initial hardness of about 40 GPa to a treated hardness of about 75 GPa.