Here are some factoids to toss around in pursuit of UDD on an industrial scale. This does not seem to be what Holmlid is doing, but it makes sense anyway, at least on paper.
Magnetite is iron-oxide with the chemical formula is Fe3O4 ratio 1:1.33 (iron to oxygen atoms) Hematite is iron-oxide with the chemical formula is Fe2O3 ratio 1:1.5 (iron to oxygen) There are striking differences in the physical properties of the two oxides especially electrical conductivity and magnetic susceptibility. Oxygen can be strongly paramagnetic and can cause superparamagnetism at the nanoscale. Thus varying oxygen content of the oxide is the key. When hematite is combined with hydrogen and heat, some of the oxide will be reduced to magnetite and steam, but then then magnetite will be combined with steam and heat and be oxidized back to hematite. This can happen rapidly, on a time scale of picoseconds. Thus, a shifting balance between the two oxides is reached at equilibrium, when hematite is stored in the presence of pressurized deuterium and heat. The secondary results of this see-saw nanomagnetism - should lead to hydrogen densification due to magnetic interactions. The two oxides have different, but similar, physical structure, based on hexagonal nanoporosity and will hold varying amounts of hydrogen. But rapid changes in magnetization would be the avenue leading to UDD. This process may sound similar to the deuterium uptake in palladium, seen in cold fusion but in contrast the pores in iron-oxide are an order of magnitude larger and are in the range of the Casimir force, whereas the palladium matrix is too tight to benefit from Casimir dynamics. Specific gravity of iron: 7.84 g/cm3; Specific gravity of oxygen: 1.1 g/cm3. Density of Magnetite: 5.175 g/cm3 (Measured); 5.20 g/cm3 (Calculated specific gravity). Density of Hematite: 5.15 g/cm3 (Measured); 5.30 gm/cm3 (Calculated specific gravity). Thus we can see that in comparing the two oxides, hematite should be less dense (than it is in actuality) based on its higher oxygen content and the lower specific gravity of oxygen. This means that magnetite has slightly greater nanoporosity but both are significantly nanoporous. It is the change in porosity, when going from H-to-M-to-H rapidly - which is important. When hydrogen enters the picture, as a gas - it is stored in the nanopores and becomes reactive, based on temperature - but as the oxides change from H (hematite) to M (magnetite) and back again, trillions of times per second, the net effect is like a pump, or a piston engine. Rapid change is pressurization and magnetization could set the stage for gradual densification over time. Temperature control would be important. Based on these parameters, it should be possible to make significant amounts of UDD over an extended time period, simply by storing pressurized deuterium in iron-oxide - at temperature near the Néel temperature of ~950 K (675 C) for weeks to months. Something similar may happen with nickel-oxides at lower temps, but being less reactive, not as robust. The chances of success with this kind of static densification technique would seem be far greater with iron-oxides than nickel oxides. Jones
