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When the hydraulic pressure is removed from the well, small grains of hydraulic fracturing proppants (either sand or aluminium oxide) hold the fractures open. Hydraulic fracturing began as an experiment in 1947, and the first commercially successful application followed in 1950.
This is especially true in the area of oxygen therapy. Although oxygen was first used as a therapeutic agent as far back as 1799, the modern era of oxygen therapy had to wait for the technology to be âinventedâ so oxygen could be safely and conveniently delivered to the home.