PMC

Noise levels are expressed as median (L₅₀) and upper and lower 5% percentile (L₅ and L₉₅) sound pressure levels in third-octave bands. a) Comparison between ambient noise spectrum (converter stopped, solid blue line; percentiles: dot-dashed blue lines) and noise spectrum recorded with the wave energy converter running (red dashed line; percentiles: red fine dashed lines). b) Comparison between ambient noise spectrum (converter stopped, solid blue line; percentiles: dot-dashed blue lines) and noise spectrum recorded during start and stop of the converter (red dashed line; percentiles: red fine dashed lines). Self-noise of the recorder was below 80 dB re. 1 μPa in all third-octave bands. c) Results of pair-wise Mann-Whitney tests (p-value) for all third-octave bands comparing converter running to ambient noise. Broken line indicates 5% significance level, adjusted for multiple comparisons (Dunn-Sidak correction). d) Same as c), but comparing start and stop of converter to ambient noise.

Effect of temperature on pressure leaching behavior of PGMs from NaOH-preconditioned autocatalytic converter at NaCN concentration, 5.8 g/L; pO₂, 150 psi; bio-cyanide solution pH, 11.6; and time, 60 min.

Effect of oxygen pressure on autoclave leaching of PGMs from NaOH-preconditioned autocatalytic converter at temperature, 150°C; NaCN concentration, 5.8 g/L; bio-cyanide solution pH, 11.6; and time, 60 min.

Effect of NaCN concentration on pressure leaching of PGMs from NaOH-preconditioned autocatalytic converter at temperature, 150°C; pO₂, 200 psi; bio-cyanide solution pH, 11.6; and time, 60 min.