Pint glass small pits which aid in nucleation, allowing the gas within it to be released more easily, thus preserving the head. Without the aid of these pits a regular pint glass will keep a head for only 3 or 4 minutes before appearing 'flat'. The markings come in a variety of styles ranging from a simple circular or square hatched pattern to more complicated branding messages. Pint glass collecting is an increasingly popular way for individuals to commemorate their visits to popular tourist destinations, most notably to microbreweries or sports arenas. These destinations often sell pint glasses adorned with their logos,
Artificial gills (human) per minute while swimming or .64 liters per minute while resting. As a result, at least of sea water per minute would have to be passed through the system, and this system would not work in anoxic water. Seawater in tropical regions with abundant plant life contains 5–8 mg of oxygen per liter of water. These calculations are based on the dissolved oxygen content of water. Artificial gills (human) Artificial gills are unproven conceptualised devices to allow a human to be able to take in oxygen from surrounding water. This is speculative technology that has not been demonstrated in a