Abstract: The present disclosure provides for cementitious shielding compositions, methods of making the cementitious shielding composition, structures incorporating the concrete cementitious shielding composition, and the like, where the cementitious shielding composition includes elemental boron and/or a boron compound, for example as boron particles. The boron particles can be homogeneously distributed throughout the cementitious shielding composition and can have a largest least dimension of about 100 microns or less. The present disclosure, in some aspects, can reduce or eliminate problems associated with minerals found in concrete aggregates, because those materials are degraded over time by neutron radiation, which leads to disorganized lattice structures, manifested as damage by radiation-induced volumetric expansion (RIVE), and potentially further damage from alkali-silica reaction (ASR).

Abstract: A motorcycle helmet defines a cavity in a hard fiber shell. A thermo-electric heat pump is mounted in the cavity, and a light metal rediator is bonded to both shell and pump. One way conductors energize the heat pump from a motorcycle battery source to pump heat from the hard fiber shell to the radiator. A flexible blatter filled with heat transfer liquid is mounted in the hard fiber shell and below the heat pump and in thermal contact with a wearer's head and the heat pump, for conducting head heat to the pump to electrically pump to the radiator for radiation to the atmosphere.