The common mineral quartz (SiO2), for example, contains four-coordinated silicon at low pressure, but it transforms to the dense stishovite form with six-coordinated silicon at about 8 GPa.
Unlike the simple squeezer, piston-cylinder, and belt apparatuses, multianvil devices can compress a sample uniformly from all sides, while achieving a pressure range with an upper limit of at least 30 GPa.
Similarly, the pyroxene mineral with formula MgSiO3 at room pressure contains magnesium and silicon in six- and four-coordination, respectively, but the pyroxene transforms to the perovskite structure with eight-coordinated magnesium and six-coordinated silicon above 25 GPa.
At room temperature, for example, all gases solidify at pressures not greater than about 15 GPa.
Although universities would be free to weight marks how they wished and also decide on whether to include marks for first-year students, the report stressed the importance of establishing a universal approach to GPA.
Oxford Brooks is the only university to have adopted the GPA system so far.
In a report, published by the Higher Education Academy, universities are urged to trial the grade point average (GPA) system, used by universities in the US, Canada and Asia, alongside the current honours degree model, over a five-year period.
The 2013-14 pilot study found that GPA gives students a more precise and internationally recognisable measure of their academic achievement.
Stephen Isherwood, chief executive of the Association of Graduate Recruiters, thinks a move to GPA would be a positive step.
GPA gives students a more precise grade by providing a cumulative score of average marks throughout a student's degree.
Sir Bob Burgess, former vice-chancellor of the University of Leicester who ran a GPA pilot study involving 21 UK institutions in 2013-14, said that GPA will help meet the need for a more precise indicator of degree grades.
