The experimentalists who have tried to generate gravity-like fields by subjecting ferromagnetic materials such as alpha iron or ferrofluids to pulsing magnetic fields include Hollingshead, Searle, Godin and Murad and others. Although partial success has been reported, most admit that full replications have been unsuccessful. However, it was Hollingshead who reported a strong gravitational effect accompanied with a release of energy and beta radiation due to “pushing protons into becoming neutrons”, the only experimenter suggesting a nuclear basis. He also reported a diminishing effect over time. This suggests an isotopic shift similar to LENR. However, he never reported generating useful power from the device.
In November of 2002 Hollingshead reported effects when he spun three pairs of counter-rotating rings composed of electromagnet stubs (looking like inward-pointing stud collars) around a central soft iron reference point (RP) stator. The RP stator was configured as a sphere, wrapped in a dielectric and surrounded by another layer of metal, thus acting as a capacitor when electrically charged. When the rings were spun synchronously gravity-like effects were reported at least four orders of magnitude higher (literally lifting boulders and crushing work benches) than M. Tajmar's micro-g experiments prior to 2006. Hollingshead also reported that when the device was stationery and spun up a dramatic drop in temperature surrounding the RP occurred.
Hollingshead made no claims regarding the pairing of electrons, as did Wallace, but like Wallace suggested that nucleonic mechanisms were in play.
Both Searle and Hollingshead reported creation of an ionized halo around their stationary devices, even though Hollingshead claimed he had never heard of Searl before developing his device. Both reported the generation of a vacuum around the devices as air was pushed outward. Wallace also hypothesized the generation of a shield effect, while Hollingshead claimed actual generation of a shield... and reported bouncing small objects off of it.
In a 2006 article in New Scientist, Tajmar similarly discussed the potential ability to create a "shield" with such a gravity effect. He said, “Levitating cars, zero-g playgrounds, tractor beams to pull objects towards you, glass-less windows that use repulsive fields to prevent things passing through. Let your imagination run riot: a gravitomagnetic device that works by changing the acceleration and orientation of a superconductor would be the basis for a general purpose force field."
When I asked Tajmar back in 2010 about Hollingshead, Tajmar replied that he did not think that effect (if true) was related to his research.
Alan Smith can tell you more (if you ask him nicely) about the chapter with Hollingshead, which still remains open.