Abstract: A swim device comprising elongated foot pockets which surround each of the feet of the swimmer, continued distally with tapers ending in neckings connected in a functional manner to blades for each foot. The neckings of the tapers of both feet may be connected to one blade (monofin). A swim device comprising a cowling of generally elongated shape which surrounds both feet of the swimmer, continued distally with a taper, ending in a necking to which one blade (monofin) is connected in a functional manner. The tapers and the hydrodynamic cross-sections of the foot pockets and of the cowling, result in stronger thrust and lower drag than in the designs of prior art.

Abstract: A method is provided for producing a solid acid catalyst having a structure including a metal core having essentially an entire outer surface covered by a layer of metal oxide including a multitude of active sites provided with Lewis Acidity. The method involves an oxidizing step to form a layer of metal oxide and a halogenating step to produce a metal oxide layer with multiple active sites exhibiting Lewis Acidity.