First a urea substance was added to turn the cooked white back into a liquid.
In a disgusting-sounding experiment that you probably shouldn't try at home, an international team of researchers have used urea, one of the main components of urine, and a "vortex fluid device" to uncook a hen's egg.
So he seals these two chemicals inside tiny capsules of urea and formaldehyde, and then mixes them into a liquid polymer and sprays it onto concrete blocks.
This process caused the urea and the formaldehyde to form, as desired, capsules containing the two concrete-healing chemicals.To deploy his capsules, Dr Chung mixed them into a liquid polymer, sprayed the mixture onto some concrete blocks and allowed the resulting film to solidify.
As the oxygen level fell, though, something else rose: the level of urea.
Indeed, a calculation Dr Ip performed, based on the volume and composition of the urine he collected in the plastic buckets, and of the head-dunking water at the end of each day, suggested that only 6% of the urea excreted by the turtles was leaving them in the traditional manner, via urine.
Each farmer then took his coupons to a local shop where he exchanged them for reduced-price seed, 50 kilograms of urea and the same amount of a nitrogen-phosphorus mix, both used as fertilisers, for which he paid about a quarter of the normal sum.
These can keep the chemical mixture safely stowed away, but they rupture and release their contents when the concrete near them cracks.To make the capsules, the team stirred together a solution of water, urea, ammonium chloride and a benzene derivative called resorcinol.
As in a car exhaust, the flue gases next pass through a catalytic converter, where the nitrogen oxides are chemically reduced with ammonia or urea.
The solution was to put the healing balm inside tiny capsules made of urea and formaldehyde.
Bagasse, the crushed dregs of sugar cane, is being burnt for energy and mixed with urea to feed cattle.
